Product Help & FAQ's

Frequently Asked Questions

A word about measurements

Transpack should have gone completely metric years ago. However, many of our customers still use inches. Our website is mostly metric, but not universally. We are working on becoming completely metric, but only as soon as the same is true of all our customers!

Rough conversion from millimeters to inches: with a calculator, multiply inches by 25 and you arrive at roughly the right mm. Conversely, divide mm by 25 and you get the appropriate inches. If you need total accuracy change the 25 above to 25.4 and your result is accurate!

Weight & thickness measurements

Paper based products and plastic film thicknesses are measured in different standards. Paper products are normally measured by their weight which is measured in "gsm" - grams per square metre, a measurement of weight, not thickness.

Plastic sheeting, tubing and bags, are measured by their thickness and this is expressed in "gauge" (imperial) or "microns" (metric).

An explanation...

Gauge relates to thickness in thousandths of an inch, and each 100 gauge is 1 thousandth of an inch. Thus 500g is 5 thousandth thick.
Microns are thousandths of a millimetre. Thus 100 microns is 1/10th of a millimetre.
Gauge can also be approximately related to microns by dividing the gauge figure by 4. Thus, 500g polythene is 125 microns.

Secrets of Bubble Wrap

The purpose of any cushioning is to prevent damage in transit from shocks, bumps and vibrations. Different materials do this in different ways. Some (like bubble wrap) will squash and recover repeatedly while others (like corrugated materials) will squash but not recover. i.e. one good bump and they remain squashed! This is why bubble wrap has become so popular over the years; its cheap and an effective solution for wrapping, interleaving, void fill and for what it is, uses very little material.

Which size bubbles should I use?

This depends on what you are packing and how you want to use the bubble wrap. Most products can be easily and well packed in small bubble wrap. However, the large bubbles are better for delicate shapes such as wine goblets etc. The large bubble wrap is also better (and cheaper) as a void filling medium.

What's the difference between large and small bubbles?

The fundamental difference is one of softness. Large bubbles are softer and thus more suited to delicate things, unless you just need the extra thickness to bulk out a box.

Small bubbles will carry more weight. For example, if you wrapped three heavy doors in large bubble wrap you may find the bubbles bursting with the weight. In such a situation smaller bubbles will do better.

Which bubble wrap to use for repro furniture?

Bubble wrap should NOT be used on polished furniture. For some reason the bubbles sometimes get imprinted on the surface. We recommend using PE Foam in 2.5mm thickness. This is made for the furniture industry and is ideal for any highly polished wood surface.

Can I use bubble wrap to cover my swimming pool?

No. Packaging bubble wrap is not tough enough to withstand the constant movement. Normal bubble wrap is made of polythene which is not UV stable i.e. it disintegrates in sunlight. You will need the special material sold by pool companies.

Can I get bubble bags made to a special size?

Yes - but the minimum quantities are very high - in the many thousands.

Cardboard Boxes: Choosing the right one

Cardboard boxes come in a variety of specifications, offering different thicknesses, layers, folds, flaps and sizes:

How are cardboard boxes measured?

Standard cardboard cartons, of the kind Transpack supplies, are always measured INTERNALLY: Measurements are: length X width X height.

The longest dimension of the flaps runs along the Length. They meet across the Width.

What is a cardboard box made of?

Boxes can be made from solid fibreboard (greyboard, chipboard or even strawboard) or from corrugated board where a fluted paper material is glued between 2 layers to create a board of greater strength. All the cardboard boxes we supply are of the latter style, often referred to as corrugated cases or cartons.

What is meant by "single wall" or "double wall" boxes, and which is stronger?

Single wall is ONE layer of fluted material between two boards. Double wall is TWO layers. This makes double wall cardboard boxes much stronger, in fact it is more than twice as strong, and if you are moving house this is the box we would recommend.

Are there different strengths of the cardboard?

Yes. While most boxes are based upon a standard board they can be made from heavier material to special order.

Can I get White cardboard boxes for my products?

Yes. For boxes there are 2 kinds of white. The most common is a mottled white. It has an good appearance but is not an all over pure white. If this is not white enough there is a High White available on special order.

Do I have to order more to get White boxes?

Yes. The minimum quantites for white boxes are much higher than those for the normal brown ones. For mottled white this might be 5 times as many. For High White it could be 20 times. The exception is our range of self-locking postal boxes which are nearly all Mottled White.

Do I need "single wall" or "double wall" boxes?

You will need to consider various factors such as weight to be carried, method of transit, height of stacking and "integrity" of contents. In general terms single wall cartons are deemed to be adequate only up to about 5kg weight of contents and light handling. If the contents are very robust and a tight fit in the box a greater weight may be possible. If you are despatching this product by courier or postal carrier, a double wall box is likely to cope with the multiple handling much better.

How do I pack my boxes to minimise damage?

Pack tightly! No matter what the content is it must NOT be allowed to move about in the box, even if the box is dropped. There is a wide variety of cushioning and filling material available for fragile items or mixed consignments and you may have to experiment to arrive at the right solution for your product. 

Can boxes be made to my special sizes? And what is the minimum amount?

Standard boxes can be made to any size within reason. The minimum quantity for any normal use is 100, varying according to size required. You should be aware, however, that the price for 100 can often be 3 times the price (each) for 200 or 300.

Non-standard boxes, such as special shapes or "die-cuts" are normally subject to much higher minimums. For example, if you wanted a made to measure self-locking postal box the minimum would be at least 1,000 and there would also be an extra charge for the cutting tool.

Can cardboard boxes be printed?

Yes. Most of the box making machines have flexoprint facilities built in. There will be minimum runs of around 500 or more, and plate-making is an extra cost. Multiple colours do become very costly as they involve multiple runs and colour changes. It should also be noted that the print method is "flexography" which cannot cope with half tones or close registration.

Can I get coloured cardboard boxes?

Yes. This is subject to large minimum orders - perhaps as many as 5,000 boxes,  and a significant cost increase.

Can I get wax-coated cartons for export?

Yes. This is subject to a minimum order and takes a little longer but it is no problem.

Can I get boxes that will go through a letter-box?

Yes. Some of our self locking postal boxes will go through a standard letterbox; three of these sizes have been designed specifically to fit through Royal Mail’s "Large Letter" or "Small Parcel" Slot. Additonally, our PIP boxes (pricing in proportion) are also available to help keep your postage costs down and fit through Royal Mails ‘Large Letter’ slot.

Polypropylene Bags: A clear explanation

We supply bags made from a plastic film called OPP (oriented polypropylene). Polypropylene is a highly stable plastic film unaffected by most acid or alkaline materials; thus it is widely used for packaging food and can be considered "food safe". Nonetheless, it can be affected by some oils. Polypropylene should not be confused with Cellophane™ or NatureFlex™ which are produced from cellulose, an extract of wood pulp. We now stock a range of NatureFlex™ bags which are 100% home compostable.

All our plastic based Greetings Card Bags and Artwork / Photo Bags are made from OPP. All these bags are made from 30 or 40 micron film and are self-seal, with a flap and removable adhesive. (i.e. they can be opened & reclosed many times). These bags are not heat sealable.

All of our range of clear bags are food safe and a food certification certificate is available on request. Apart from those mentioned above, they do not have a resealable flap and therefore can be tied with ribbon, sealed with a sticker or heat sealed.

We have several different types of cello bag for gifts, which are outlined here:

Gusseted Bags have gussets in the sides which allow the bag to open more widely.  The also have a crimped bottom seam, and as such don't have a pre-formed base.  As the bag is filled the gusset opens out and the bottom of the bag folds under forming a base. Ideal for items like rice which will fill the bag completely and give it a nice shape. Also good for heavier or bulky items, chocolates, sweets and popcorn. These bags are 40 microns so slightly thicker than the bags below although you may not notice a huge difference. If you need an airtight bag you should choose this type, but you will need to use a heat sealer to seal the top edge of the bag to make it airtight. This need not be a very expensive exercise and we have lots of options and advice. Visit our heat sealer pages for help.

Block Bottom Bags have a pre-formed rectangular shaped base.  They won't open as widely as a gusseted bag so if your item is bulky it might be slightly trickier to place in the bag, although the pre-formed base may cancel out this problem. These bags are 30 microns and crystal clear. They are not suitable for products like flour as the block bottom seal is not airtight, and you may get some leakage. Use a gusseted bag for flour.

Silver Card Base Bags are essentially a block bottom bag with the addition of a card base which has been glued to the outside of the bag. It gives the bag extra stability and it will stand up nicely on a shelf, unsupported. Again these bags may leak powder so they are no good for flour and similar products. They are 35 microns so slightly thicker than the plain block bottom bags. It's important to note that the card is only silver on one side, and its on the underside of the bag. The other side, facing into the bag, is a creamy colour and would be invisible once product has been added to the bag. We also stock a range of these bags which are pre-printed - some with Christmas designs, butterflies and a fruit design. We call these our Patterned Silver Card Base bags. They are popular as party bags and wedding favours.

Transpack's Silver Card Base Bags with Side Gussets give good stability due to their card base, and they open out a little wider thanks to the gussets. They will hold their shape well.  Also made from 35 micron polypropylene they will certainly show off your products, whether they are confectionery or beauty products.  Again they are not recommended for powdery products.

Window Bags are a good choice if you want to introduce a little colour to a display, or use a more eye-catching bag.  They are made from a printed polypropylene film although they look like coloured paper on the back, all in quite earthy tones. The front is crystal clear meaning your products are completely visible from the front, and the coloured background will make them stand out beautifully. These bags also have card bases, although they are not silver - they are a natural colour.

If you are in any doubt which to buy, or would like help with the measurements have a look at the video below - it will help!

Our Garment Bags are made from standard polypropylene, have a self-seal flap with removable adhesive strip and are hole punched to avoid suffocation. They are also printed with a suffocation warning notice. If you are looking for a bespoke size, or a printed bag we would be very happy to quote. 

Polypropylene bags are not biodegradable, although they are recyclable.

How many cards and envelopes can I get in a greetings card bag?

It's impossible to say. The standard size bags are designed to take one card and envelope in heavy card/paper; but we know of users who have got 5 cards and envelopes in each bag. It all depends on the exact trim and the weight of paper used for the cards and envelopes. The C6 and C5 sizes will take multiple cards. How many you'll get in will still depend on the weight of paper used. If you have any concerns, please ask us for a sample.

Can I get a special size made?

Yes. Subject to a minimum quantity, usually about 5,000 but it can be more if you are looking for a small bag. If you are having cards printed it makes economical sense to have them trimmed to a standard size. That way both the bags and the envelopes will be cheaper and less of a challenge to get hold of.

Can I get the bags printed?

Yes. This is subject to a minimum quantity, if you are interested in this service please contact us and we will be happy to put together a quote for you.

Are the Artwork / Photo bags made to fit photo mount sizes?

We cannot be sure about this as mounts seem to vary. We stock a common range of bags that are most popular. We clearly supply the measurements of these bags on our website. Please let us know if you require sizes that are not available on the website and we will endeavour to help you.


Heat Sealing Polythene: Tips & Advice

Our standard range of heat sealers are suitable for light and medium duty applications. They are  "impulse" sealers which means the element only heats up for part of a second to weld the polythene. This sealing time can be adjusted to allow for differing thicknesses of polythene.

These sealers will seal Polythene and Polypropylene only, no other common plastic films.

They are available up to 500mm wide and will weld up to 2 layers of 1,000g (250 mic) film.

Beyond these parameters we can offer further ranges of sealers up to 5 feet wide and with double sealing elements, cable or chain operation, magnetic seal controls and programmed heating and cooling.

Sealers like these start at about £380.00 and get more expensive as you choose more sophistication.

The following FAQs should help to answer some of the most common queries...

Can I use my heat sealer to seal polypropylene bags?

All of our clear bags are actually Polypropylene bags and as such CAN be heat-sealed on our impulse heat sealers. True Cellophane is not plastic, its actually paper so it cannot be heat sealed at all – it must be glued or crimped, however none of our bags are true cellophane .

I have a "Packer" sealer purchased from you 2 years ago. Can I get spares for it?

Yes, we keep a full range of repair kits for sealing components but any repairs that are "below the case" would be subject to inspection and quotation. As the machines are pretty cheap in the first place such "below the case" repairs are usually uneconomical.

Our welds are coming out all puckered, what is wrong?

This is caused by too much heat i.e. you need to turn down the dial until the puckering stops but the weld is still sound.

Our welds are bursting open when we fill the bag.

This is probably due to slightly insufficient heat. Try turning up the dial by just half to one point at a time until the welds hold properly.

After a few welds I can see a blackish build-up on the teflon over the sealing strip. What is this?

Its melted polythene! You may have your heat turned up just a bit high and this is causing excessive melting during the welding process. The excess melted polythene ends up on your teflon cover. Simply wipe it off and turn the heat down. Heat sealers should always be run at the minimum temperature at which a successful weld can be achieved.

What number on the dial do I need for 250g clear polythene?

It is not possible to say. The heat sealers all vary slightly and so does the polythene. One batch of polythene may weld nicely at number 3, and the next batch with exactly the same spec needs number 4. The machines, the polythene and the ambient working temperatures all vary.

I have an old Pifco heat sealer but it won’t work on your heavy duty bags. What is wrong?

The Pifco sealers were designed for domestic use only and don't have the wattage to weld heavy duty polythene. You’ll need to upgrade to a more industrial heat sealer to cope with heavy duty bags.

Can I get a machine that will weld a bag "standing up"?

Yes, most of the larger industrial heat sealers we supply can be mounted with the jaws operating in the vertical instead of horizontal. There are special stands that hold the machines ready to weld the top of a standing sack.

Jiffy Bags and their uses

Jiffy Bags seems to be the name given to any kind of mailing envelope with a paper outer and some form of cushioning as a liner. In fact, the original Jiffy Bag was the Padded Envelope introduced by Jiffy in the 50’s and still going strong. This Padded bag has a very strong pure Kraft paper outer and a lining of macerated paper fibres. These fibres actually bulk up in use so the bag’s cushioning properties improve as it travels! The "Padded Bag" remains the only truly eco-friendly postal bag as it is easily reusable and recyclable.

Jiffy Airkraft Bags, as well as most of their competitive brands, have a slightly different kind of pure Kraft outer and are lined with small bubblefilm. In the case of Jiffy Airkraft bags the bubble film is laminated to the outer making for a very strong pack.

These bags are pretty straightforward, but here are some of the common questions:

I am sending single CD’s in jewel cases; should I use padded bags?

No, just use a standard Airkraft bag. Unless someone jumps on it, your CD will be fine. This would be different if you were sending a number all together.

How do I work out if my boxed kit will fit in the bag?

Take a soft tape measure and wrap it round your box in both directions. Now, halve these measurements and you have the basic bag dimensions. Now find the nearest Jiffy bag size that will take this size (plus a bit for packing).

I want to send slim hardbacked books. Can I use a Jiffy bag?

It depends on A) how slim the book is and, B) how hard the cover is. Many hardback books will suffer from compression on the corners whilst being otherwise fine in a bubble lined bag such as Airkraft. Very slim volumes (up to about 6 or 7mm) probably won’t suffer as much. If you are in doubt we can supply you a sample to try. Consider using our book boxes for maximum protection.

Can I send large bolts and nuts through the post in an Airkraft bag?

Not a good idea. There is a risk of such heavy items breaking through both the bubble and the paper in transit. Better to use the Jiffy Padded bag and keep them taped tightly together before they go in the bag.

Can I send china mugs in a Jiffy bag?

No. Not even in a padded bag. Use a box.

Can I get a special size Jiffy bag made?

Yes. There are substantial minimum order quantities between 25,0000 and 40,000 depending on the size.

Are Jiffy bags recycled?

Partly. The lining of Jiffy Padded bags is made entirely of recycled paper fibres. The outer of the bags is made of pure Kraft paper from sustainable forests.

Can Jiffy bags be recycled?

The padded bag is totally recycleable as it is all paper. The Airkraft bags, however, have the bubble film laminated to the paper for extra strength, so they are more difficult to recycle in the normal way. Both are easily reusable.

Kraft Paper: Fact Sheet

Kraft paper is a special quality of paper designed to have greater tear, burst and wet strength than normal papers. It comes in a wide variety of forms, but all the kraft we supply is Pure Ribbed MG kraft on rolls.

  • Pure - means it is not weakened by the addition of waste elements.
  • Ribbed - it is slightly stronger in the ribbed direction.
  • MG - "machine glazed" on one side. Use this as the outer of your parcel - it is more impervious to hazard.
What is imitation kraft?

It's an imitation material that is made of part or all recycled materials. Some imitation kraft is almost indistinguishable from the real thing - but some of it is very poor and has little inherent strength.

Can this kraft be used to mask up cars for spraying?

Yes. But there is a specially made "masking kraft" supplied by many auto factors which is more economical.

I want to wrap 1" dia 4ft metal tubes - 6 per pack. Can I use kraft?

Yes. It does make sense to strap them together first before you roll them up in the kraft. The kraft WILL NOT prevent denting.

Is the kraft waxed?

No. Our kraft does not have a wax coating. Like bitumenised kraft (kraft union), waxed kraft is available for special order.

Can I get a dispenser for kraft rolls?

Yes, we supply a Counter Roll Holder which can be mounted on a bench or a wall.

Can I get kraft in cut sheets?

Yes. There are some standard sizes available to order. Lead time is about 2 weeks.

Can kraft be recycled?

Yes and it also comes from sustainable forests.

Mailers & Mailing Bags: A Guide

Although Jiffy bags can be considered mailers, what we refer to as mailers or mailing bags are essentially polythene envelopes. These quality postage bags all have flaps and sealing strips with a non removable adhesive.

Our ranges in this area are:

Can I get mailers printed?

Yes. There are minimum quantities for custom postage bags (about 5,000 for opaque bags) but printing on one or both sides is not a problem.

Can I get special sizes made?

Yes. Also subject to minimum runs of 5,000 - 10,000 depending on the bag size.  The smaller the bag, the higher the minimum quantity is likely to be.

Could I use these for small wooden kits?

Not without some form of wrapping to protect the bag from the edges of the wooden parts. A Jiffy bag would probably be more appropriate.

What weight will the opaque bags take?

They will take quite a lot of weight, but if you then consider handling, throwing, dropping etc. I wouldn’t put more than 3 or 4 kilos into one. They are really designed for clothing, papers and other similar items.

How thick are the grey & blue mailing bags?

They are mostly 60 microns, the same as those you might get from well-known mail order companies. There are also a couple of heavy duty ones available.

Can I stick a label or document envelope on the mailers?

Yes. Most types of adhesive will stick to them well.

Packaging Tapes - Help & Advice

The most commonly used tape is PVC or PP tapes which are easy and quick to apply. You can also get the more eco-friendly range of water based, gummed tapes sold with water dispensing machines.

These packaging tapes are often referred to as "self-adhesive", but they are not. In fact all modern packing tapes are activated by pressure. Without pressing the tape down it will hardly stick; and, the better you press it down – the better it sticks! This is why it is important to use a proper dispenser which applies the tape with a roller to press it down.

Another feature of such tapes is "curing time"; after applying the tape to your package there is a delay before the tape reaches it’s maximum adhesion. In warm weather this maybe an hour or two, longer if it’s cold. It’s better to keep packages out of direct sunlight during this time.

Which packaging tape should I use?

For normal packaging applications there are three types of adhesive tape.
These are polyvinylchloride (PVC), polypropylene (PP) and silent (coated) polypropylene. Due to its environmental impact PVC tape is getting less widely chosen. PP tapes, on the other hand are much more environmentally friendly, cheaper and equally effective.

Cold working

No tape works well when its really cold and it pays to keep the rolls in a warmer place. However, if your boxes are going to end up in a freezer it makes good sense to use PP tape and not PVC.

Unwind resistance

PVC tapes have a natural unwind resistance which, when used in a dispenser, pulls the dispenser roller down onto the package. PP tapes do not have such resistance and so need a "braked" tape dispenser so the resistance can be added.

Noisy PP tapes

Normal PP tapes can be quite noisy as they unwind (its a good sign) and when the tape is being used constantly this can be a nuisance. To overcome this problem we also have a special PP tape which is coated to reduce the noise.(Silent PP - also referred to as GP Packing tape).

How do I apply packaging tape to heavy boxes for export?

For most standard cartons it is sufficient to bring down the flaps of the box and then run a length of tape along the length of these so the join is under the middle of the tape; the tape should run 50 to 75mm over the edge onto both ends of the box. It is important that the tape is pressed firmly down onto the box to ensure good adhesion. Some users start with a "holding strap" of tape across the flaps to hold them in position while the main length of tape is applied.

For heavy and export boxes it is advisable to add a further strip of tape across the ends of the flaps – this hold the ends of the flaps onto the ends of the box. This is referred to as "H" sealing and provides a very secure package. Smooth all the tape down with a little pressure, for good adhesion.

What if my export country refuses plastic tapes?

In this case you can use gummed paper tape through a benchtop water dispenser. Gummed tapes can be dispensed by an inexpensive "pull & tear" dispenser. For reinforced gummed tape (more usual for exports) you will need a slightly more sophisticated dispensing machine which is capable of cutting the tape. Because everyone wants something slightly different we don’t keep gummed tapes in stock - but we regularly supply it. We do also stock a self adhesive paper tape, which can be recycled with the box, and offers a great eco-friendly alternative.

Can I get my packaging tape printed?

Yes - email us your logo and details and we will send you a quote:

Polythene Bags - Your Questions Answered

Safety in use

Of all the wide range of plastic films, polythene (PE) is by far the safest to use. Being chemically inert it does not impart any kind of residue or taste and is impervious to most chemicals, even acids. So it is suitable for every kind of application; all our polythene bags are made from “food safe” quality film.

Polythene bags and child safety

Light duty (especially) and medium duty polythene bags can both cause suffocation if the bag is pulled over the head. Subject to minimum quantities bags can be perforated to avoid this risk, but our normal stock bags are NOT perforated in this way.

Heavy duty bags are less conforming and, as such, are very unlikely to represent the same suffocation risk. As part of our range we do offer some self-seal clothing bags which are both perforated and printed with a standard warning notice. The link below will take you straight to them.

Garment bags

Are Polythene bags watertight and airtight?

NO. Polythene is "air-permeable" so it cannot be used for vacuum-bagging. There are special nylon coated polythene bags available for this purpose. Our polythene bags are not recommended for liquids as they are not designed for this, and although they may hold liquid for a short period of time, they will start to leak.  Similarly you won't be able to make our polythene tubing into bags for liquid. 

What "duty" should I use?

Most polythene is much stronger than you think, and most users choose a heavier bag than they really need. But here is a guide to the duties:

Our "duties" usually conform to the following thicknesses:-

  • Light Duty - 100/120g = 25-30 microns
  • Medium Duty - 200 / 250g = 50-62 microns
  • Heavy Duty - 400 /500g = 100 – 125 microns


Light Duty - This is typically the film that is wrapped around a new electrical appliance inside it’s box. It is glossy and very clear. It has a very little resistance to sharp corners and edges. Because it is so light and "floppy" it can be harder to pack with - especially if the item is nearly as big as its bag. Light duty is mostly used as a means of keeping things clean and free of dust. However, if you are simply bagging up such items as clothing etc for storage then Light duty bags are fine.

Medium Duty - is twice the thickness of the above. The clarity and gloss is still good but it will cope with some corners and edges (though, not metal). It is also much easier to pack with as it tends not to collapse as you’re filling it.
Medium duty is mostly used as a means of collating items together in one pack. If you want to pack such things as cables, card & flat wood modelling kits, or even plastics plumbing & drainage items our Medium duty bags are ideal.

Heavy duty - has 3 jobs; to carry weight, to cope with harder and sharper contents and to provide extra rigidity both when packing and when displayed. Builders use this weight of polythene when packing shingle or sand into 25kg bags. If you are still in doubt, ask us for a sample or two.

Polythene and the environment

Normal polythene is not biodegradable, though it IS "photodegradable". This means it will not break down when buried in a landfill, but bags will break down in sunlight. If you have ever wondered why our countryside isn’t covered in them it is because most bags will break down into dust in less than 12 months.

As this subject has become a more global issue recently we have now written a whole article within these pages. See "Plastics and the Environment".

Sizing polythene bags

On our website most of our bag sizes are shown in millimetres. To convert roughly to inches divide by 100 and multiply by four. E.g. if the bag is 375 x 500 this converts to (3.75 X 4) x (5 x 4) = 15 x 20 inches. It’s not exact, but it's very close. Alternatively, go to our "measurements" section.

Manufacturing Tolerances

The polythene film extrusion process is complex and affected by external conditions like heat, therefore factories are unable to guarantee the size of bags exactly, and a degree of manufacturing tolerance is required on every polythene product. It should be noted that our measurements are the internal dimensions.

Width - Plus or minus 3mm (0.125") or 2%, whichever is greater.

Length - Plus or minus 6mm (0.25") or 2%, whichever is greater. The external dimensions are cut to cut and will therefore include a bottom skirt of about 8mm on end weld bags (apart from "grip seal bags" which are measured from the grip seal to the bottom of the bag).

Gauge - Plus or minus 10%.

Quantity - BESPOKE MANUFACTURE ONLY, Plus or minus 10%.

Sealing & closing polythene bags

Some "polythene bags" come with their own closure method. This can be a "press-together" gripper (like our "Self Seal Again bags") or self-adhesive tape on a flap. The most common form of closure though, is heat sealing. This is where a hot wire is pressed onto the top of the bag to weld it together along a thin line. For widths up to 400mm there are very inexpensive machines that do this very effectively and are only hot during the actual welding cycle. You can use this link to view our range of heat sealers.

Printed polythene bags

Plastic bags of most types are printed as film, before they are made into bags. This means that the minimum that can be printed runs into thousands, depending on the thickness of the material and the width of the ultimate bags. There is no hard and fast rule on what these quantities are; this depends on the machine to be used, the number of colours and the dimensions of the bags. To assist your calculations consider the following guide: 

Based upon an average bag of 300mm x 400mm printed 1 colour on 1 side the minimum quantity is likely to be...

  • Light duty - 15,000
  • Medium duty - 10,000
  • Heavy duty - 6,000

For smaller bags the minimum quantities get much higher. For multiple colours the minimums also get higher.

N.B. Polythene does not easily hold a print, there is a tendency for it to rub off. To prevent this happening any film that is going to be printed is specially treated in a preparation. Standard stock bags are not treated in this way; as a result please do not consider buying a few and getting them screen printed. The print may fall off!


Heat Tolerance

If you are using these bags for sterilisation or other heat processes, LDPE will start to soften at around 70 degree C and will melt around 110 degree C.

Specification & Conformity - Stock polyethylene

COSHH (Control of Hazardous substances)

Polyethylene is a non hazardous material under the law. Toxicity is Nil. All our polyethylene conforms to European Directives on Heavy Metals.


When burnt it turns to cardon dioxide and water. No toxic fumes are given off and residual ash (0.25% only) is non toxic.


Polyethylene is not biodegradable (though it is photo degradable). However, it does not give off leachates or methane.


Our polyethylene is 100% recyclable.


All our stock polyethylene conforms to EU Commission Directives 90/128/EEC; 92/39/EEC; 95/3/EEC and 96/11/EC Section A, as well as UK law on polymer specification for food contact. (excludes refuse sacks and polythene sheeting).


All polyethylene made to specific customer requirements (except BR and STR codes) is blown using virgin raw materials with resultant density of 0.924 (ASTM D1505)

Polythene Carrier Bags - Help & Advice

The plastic carrier bags we supply are all square cut bags with cut-out handles and a gusset at the bottom of the bag. We do not supply the very thin (usually striped) bags often used on market stalls.

Standard bags are 120g (30 micron) with a cut out handle that is reinforced with an extra layer.

Heavy Duty bags are 180g (45micron) bags but they are twice as thick in the handle area. All our heavy duty carriers are of printable quality.

What is the smallest quantity that can be printed?

The minimum order quantity for printed carriers is likely to be 5,000.

How long does printing take?

Once you approve the proof a single colour print will take about 3-6 weeks, subject to time of year. Multi-colour prints take longer.

What extras are involved in the printing costs?

The extras that most people forget are the printing plates (called stereos). These cost start as low as £65.00 each and upwards, depending on how many colours you are printing, size of print and how many sides you are printing. 

Can I get carriers with rope handles?

Yes, you can - but we do not supply them. 

Can I get carriers that are smaller than the standard sizes?

Yes. But there is often a high minimum quantity for special sizes. Please contact us for a quote.

If I approve a proof immediately - what is the fastest turnaround on a single colour print for 1,000 carriers?

If everything is done as fast as possible you could get your bags in 2 - 3 weeks. The closer you get to Christmas the longer the leadtimes will become. 

Can you reproduce a photograph on a carrier bag?

Sorry, we cannot. The kind of printing we use cannot cope with half tones or even very close register.

Polythene Layflat Tubing Explained

Polythene layflat tubing (usually referred to as just "layflat") is an endless and seamless tube of polythene in exactly the state in which it comes from the extrusion machine. It is a versatile product that allows you to make bags of different sizes for different items.

How can I secure the ends of my layflat?

You can tape the ends, some use a stapler and you can heat-seal the ends closed. You can even tighten cable ties around the ends!

Is layflat tubing watertight?

If you are planning to make bags which will be filled for short periods they will be watertight, but after 24/48 hours you may see some leaking. You would also need to use heavy duty, or double welds.

Can I freeze layflat wrapped round fish?

Yes - polythene is temperature stable in a domestic freezer. It is not suitable in commercial freezers because the temperature is too low, and drops too quickly. It will cause the polythene to crack. For this purpose you will need the additive EVA which reduces stress fractures and is available on special order with a minimum order of 10 rolls.

Can I use layflat as air-ducting?

Yes - layflat can be used as cheap air-ducting; not only that, but wherever you want extra air simply make a hole in the duct! It can also be used to carry air-born products into silos, etc.

What is the diameter of 12" (305mm) layflat?

Our listed layflat dimensions are half the circumference (i.e.the circumference is twice the width when laid flat). This means that a 305mm wide tube does NOT fit a 305mm dia pipe.

To go over a 305mm pipe the layflat circumference would need to be 305 x 3.142 (Diameter X pi) = 958mm This is twice what the laid flat width would be; so - halve it for the right width, in this case 479mm. The nearest available size is 508mm (20") - a nice fit with a little to spare.

Can I make my own bags from layflat tubing?

Yes, you’ll need a heat sealer with a cutter to make life easy. If you are packing components of varying lengths but a common width, layflat is the ideal solution. It saves stocking loads of different size bags.

What duty should I use to pack a steel angle-iron?
What duty should I use for packing curtains?

For these the Medium duty will be sufficient, but not if you are shipping them by couriers. In that case use Heavy duty.

How long are the rolls of layflat tubing?


Heat Tolerance

LDPE will start to soften at around 70 degree C and will melt around 110 degree C

Polythene Sheeting Help

Much of the basic information about polythene bags and polythene layflat tubing also applies to polythene sheeting. One feature of sheeting is different - most polythene sheeting is made from recycled materials. This makes it unsuitable for contact with foods.

What thickness do I use for my application?

Polythene sheeting comes in 3 thicknesses, approximately 250g (Light) 500g (heavy) and 1,000g (ultra heavy).

250g sheeting is very good for light covering and dust sheeting. In its black form it is also widely used as a horticultural mulch and weed suppressant.

500g sheeting is much tougher. In this strength it is widely used for export case lining and temporary shrouding in sheltered situations. If you want to wrap machines for despatch this is the material to use. If you wanted to store a few pallets outside for a few weeks, protected from the rain etc this thickness is ideal - also good for long-term storage under cover. All our coloured sheeting is 500g (Heavy).

1000g sheeting is very, very thick and strong. It is often used by the marine industry to cover or "skirt" yachts and boats that are dry-docked and otherwise open to the elements. This thickness is also used in the building and decorating trades as a floor covering as it is less likely to ruck under foot. Caution should still be exercised, though - it is slippery.

Our Spa body wrap material is made from pure, food safe polythene in conformable 120g film.

Strapping - A Quick Guide

Box & pallet strapping comes in a number of materials including steel, nylon, polyester and polypropylene (pp). Most of our strapping is 12mm wide pp (or polypropylene) in varying strengths, although we do not stock steel strapping we can bring it in on special order, for greater strength. 

Strapping is still widely used on many items especially where products on a pallet might otherwise prove unstable (rolled products, for example). We supply edge protectors to combat the straps from "biting" into softer items such as boxes, so if you need to strap boxes we would advise using these too.

Strapping can be secured with plastic or steel buckles where the tension is applied by hand, or with "semi-open" seals where the tension is applied by a tensioning tool.

Shrink, Stretch & Cling Film - An explanation

There is a huge confusion about these packaging films. Here is the definitive explanation:

  • Shrink film: A plastic film made of PVC, PP or polythene which is made to shrink when heat is applied thus tightly wrapping items packed in it. The heat is applied by a tunnel or a heat gun.
  • Stretch film (Pallet Wrap): Often referred to as "shrink film", "pallet wrap" or "cling film" this polythene film is stretched into place around a pallet or bundle and will stick to itself to form a sort of elasticated bandage with a strong hold.
  • Cling film: Is the flimsy, domestic and food safe version of stretch film.

Our stretch film/pallet wrap is mostly cast material meaning it is not sticky to handle and it is silent in operation. We offer medium, heavy & ultra heavy duty strengths, a 500mm wide Black film (blown film) plus a 100mm wide roll for bundling. All our stretch film is made from Virgin material.

I have large pallets of boxes of duvets. Which stretch film do I use?

For light boxes like this always use the medium duty stretch film to keep any crushing of the boxes to a minimum.

How do I wrap pallets with stretch film?

Go round the pallet twice at the bottom making sure the pallet itself is overlapped. Now wind the film round the pallet stretching it as you go. Make sure you overlap the previous layer by at least 30%. When you get to the top wrap twice round again and tear off. 

Is the dispenser absolutely vital when applying stretch film?

No, its quite easy to apply the film without one. But for bundling the dispenser does make a huge difference.

What is the difference between cast and blown stretch film?

Blown film is tougher than cast and has more ‘cling’ making it stick to itself well. It has a slightly dull appearance but is ideal for heavier loads.  Cast film definitely has its benefits though – it is clearer and can be used easily with scanning equipment.  It also unwinds more quietly than blown. Cast film will stretch more easily which can be a benefit but if securing a heavy load this can cause shifting.

Do I have to have an L-sealer for the shrink film?

No, you can use a simple shrink kit and heat gun.

Can I get shrink film or stretch film printed?


Tissue Paper - A Guide

Our tissue paper range is all 16gsm to 19gsm. All grades are made in Acid Free quality.

Are the colours always the same?

Broadly yes, but they will vary slightly from batch to batch. Even the White tissue papers can vary.

What is "Acid Free" tissue paper for?

Acid free tissue paper is made PH neutral so it is less likely to cause any tarnishing of bright metals wrapped in it.

What is Jewellers tissue paper?

A premium crisp but softer white acid free tissue paper ideal for jewellery, silverware and all delicate items that need conformable and tarnish free packaging. This tissue is unglazed, and not machine finished.

Are the White tissue papers bleached?

Yes. We do not supply unbleached tissue paper.

Are the tissue papers non bleed?

The tissue papers are bleed resistant but we do not recommend their use in damp conditions.

Are the tissue papers recycled?

No, all our tissue papers are made from paper pulp sourced from sustainable forests. All our tissue paper can be recycled.

Can I get tissue paper printed?

Yes - Email us with your requirements. The minimum order is 10 reams, however 25 or 50 reams would offer much better value for money.

Self Seal Garment Bags

Our garment bags are made from polypropylene. Designed to both protect your products and showcase them at the same time, they are the ideal way to present your garments to your customers.

The packaging which you use often presents your new customers with their first impression of your business, and with so much competition in the marketplace companies can’t afford to ignore this. Knowing that you care about your products after the point of sale, and are keen for them to arrive with your customer in perfect condition, will give your customers huge confidence in your brand.

A June 2015 survey by a polythene manufacturer showed that customers satisfied with their packaging are 57% more likely to reorder, and 95% say that poor or damaged packaging has a negative impact on their perception of your company.

Most of our garment bags are made from 30 micron polypropylene. We also stock a 40 micron range in 3 sizes which are proving very popular. And our largest bag is made from a slightly different polypropylene (cast) in 50 microns giving it added strength. Using a bag which seals with a resealable strip will protect your products from dust, the elements, scuffing and fingerprints, and will also add to the perceived value of your product. The bags are printed with a safety warning notice, and perforated to prevent suffocation.

Have you thought about having a bespoke bag made and printed with your logo? Branded packaging will strengthen your brand identity and give your customers confidence in you. Minimum order quantities are likely to be 5,000 bags and will probably cost you less than you think. We’d be happy to quote you for a bespoke bag, either unprinted or printed – email us at

Once you have packed your products in a garment bag and are ready to send them, make sure you choose the right outer packaging too. A mailing bag is perfect for lighter products and will offer complete protection from rain or a postal box will offer strength. For added crease protection or visual effect, tissue paper is a cost effective addition to your packaging. If you need any advice, our team are ready to help you.

Plastics and the Environment

A lot has been written and said about plastics and the environment, mainly concerning the “plastic bag”. I think it is time for an honest debate!

The fact is plastics are not as eco-friendly as paper, and are certainly not from sustainable sources. At the same time, as a means of wrapping, plastics are many times stronger than paper. This means that the production of most plastics involves much less energy than paper to produce the same performance. This matters economically and environmentally.

Here at Transpack our main interest is in the most common – polyethylene (polythene to most of us) – from which comes the plastic bag.

One of the features of polythene is its sensitivity to sunlight, it degrades quickly in the open. A supermarket carrier bag may last only a few months. Moreover, as polythene is inert in the first place bags made from it will not break down into anything toxic.

This does not, however, alleviate the “problem” of polythene bags in landfill. Once you bury the polythene it will last for a long, long time. Whilst sunlight breaks it down, nothing else does. Because of this there is now a race towards “biodegradable” polythene. At the moment this is still in the development stage, though there are hopeful signs that breakthroughs are on the way. A key consideration here is the long term effect on the environment of these alternatives and not rushing headlong into creating another environmental or economic problem further down the road. For example the push to diesel powered engines has actually created more pollution not less.

There are a lot of bags out there which claim to be of biodegradability origin. It is difficult to ascertain whether such claims are justified.

What we have currently is a choice of two approaches: A) biodegradable by additive which results in a bag that will degrade in a landfill in a period of up to 5 years, or, B) the use of starch or other plant products in the manufacture of the bags that will breakdown in composting heaps, either industrial and or home, providing heat and moisture are present. The resultant residue can provide support for plant growth. Bioplastic Films must fulfill strict criteria to meet the industry recognised standard ENertification requirements.

We have no doubt that good options will come from all the work that is being carried out at the moment. In the meantime we will not rush into changing our ranges until we can honestly stand by the products and the accuracy of their descriptions and claims.

Transpack Environmental Policy

We are fully aware that the day to day operations at Transpack Ltd are likely to have an affect on the environment if they are not managed correctly, therefore we have an environmental policy to ensure that all activities are managed so that impacts on the environment are minimised so far as is reasonably practical.

  • Transpack Ltd is a long established, medium sized packaging and polythene supplier who are continuously looking to improve their environmental performance. This can be done through reducing, recycling and reusing products used within the business whilst proactively trialing eco friendly alternative products as they become available eg. compostable bags.
  • We are constantly looking for ways to minimise waste wherever reasonably possible; through the reduction in unnecessary packaging, purchasing recycled products for our own use, and through sending our used products to be recycled.
  • Currently we recycle all cardboard, pallets, stretch film, paper, ink cartridges and any polythene waste.
  • Employees in the business are encouraged to consider the environment in their actions, this if often through reusing cardboard boxes to send goods out to customers, recycling waste products as well as encouraging employees to use environmentally friendly methods of transport.
  • We use energy efficient PIR activated lighting in the warehouse and our circulation areas.
  • We have recently installed the latest energy efficient ECOTech boiler .
  • Distribution. The company considers the environment when making deliveries. We have a new ECO efficient van for multi drop local deliveries which is logistically routed in zones to to maximise efficiency and save on fuel. National deliveries are contracted out to Courier services with highly efficient routing logistics and they comply with environmental legislation
  • Environmental impacts are taken into consideration in any long term investments; when considering new leases, Transpack will take into account the energy efficiency of the possible building and of the energy costs that could be involved in running the building.
  • The company Transpack Ltd will comply with environmental legislation.
  • The Safety and Environmental Manager is responsible for ensuring and assisting the management and implementation of Transpack Ltd Environmental Policy.

If you require the environmental information on a specific product then please contact us, as we will be more than happy to help.

Cellophane ™ is a trademark of the Futamura Group


If we haven't answered your question - please call us on 02380 869999 or contact us and we will do our best to help.