Short answer: choose OPP bags (oriented polypropylene) when presentation matters: they are crisp, glossy and very clear, which suits greetings cards, prints, folded clothing for retail and craft products. Choose clear polythene bags when you need a softer, more flexible bag, larger sizes or a choice of thickness: they suit bulky items, storage, dust covers, parts and general warehouse use. OPP looks sharper but is stiffer and crinkles; polythene is less glossy but stretches and copes better with awkward shapes.
The two are often confused because both are clear plastic bags. This guide explains the material differences, compares them on the factors buyers ask about, explains gauge and sizing, covers closing, workflow and buying quantities, and gives a simple way to choose. Product details refer to the OPP and polythene bags Pack Solution currently stocks.
Contents
- What OPP and polythene actually are
- Side-by-side comparison
- Where OPP bags work best
- Where polythene bags work best
- Thickness and gauge explained
- Choosing the size
- Closing and sealing clear bags
- Clear bags in a packing workflow
- Buying quantities and storage
- Food, cosmetics and other specialist uses
- Common mistakes
- Disposal
- Questions buyers ask
What OPP and polythene actually are
OPP bags
OPP stands for oriented polypropylene. Polypropylene film is stretched during manufacture, which aligns the material and gives a stiff, glossy, very clear film. Many shops call these bags cello bags or cellophane bags, although true cellophane is a different, cellulose-based material. Our transparent OPP bags are described as crystal clear polypropylene with a glossy, high clarity finish, in 10 sizes from 6.5 x 9" (165 x 230mm) to 18 x 22" (458 x 560mm), in packs of 100.
Clear polythene bags
Polythene (polyethylene) is the most common plastic film for general-purpose bags. It is softer and more flexible than OPP, stretches before it tears, and is less glossy. Our clear polythene bags are general purpose bags for packing, storing and protecting goods from dust and moisture, in large sizes from 12 x 24" (305 x 610mm) to 36 x 48" (914 x 1219mm), in 100, 150 or 200 gauge, sold in boxes of 100, 250, 500 or 1000 depending on size.
Both are clear plastics, but they behave differently in the hand and on the shelf, which is what drives the choice.
OPP vs polythene: side-by-side comparison
The table summarises typical differences between the two materials. Individual products vary with thickness and construction.
| Factor | OPP bags | Clear polythene bags |
|---|---|---|
| Clarity and gloss | Very clear, glossy | Clear, softer sheen |
| Feel | Stiff, crisp, crinkly | Soft, flexible |
| Stretch | Little stretch | Stretches before tearing |
| Awkward or bulky shapes | Less suited; film is stiff | Better suited; film conforms |
| Puncture and tear | Can tear from a nick or sharp corner | More forgiving, especially in thicker gauges |
| Typical sizes (our range) | 6.5 x 9" to 18 x 22" | 12 x 24" to 36 x 48" |
| Thickness options (our range) | Single specification per size | 100, 150 or 200 gauge depending on size |
| Pack sizes (our range) | Packs of 100 | Boxes of 100 to 1000 |
| Typical use | Retail presentation, cards, prints, folded garments | Storage, dust covers, bulky items, warehouse use |
The headline difference: OPP is about how the product looks; polythene is about how the bag behaves.
Where OPP bags work best
- Greetings cards and prints. A crisp clear bag keeps cards clean and lets customers see the design. Our listing notes that A5 cards and prints (148 x 210mm) fit flat in the 6.5 x 9" size, and A4 sheets (210 x 297mm) fit flat in the 9 x 12" size.
- Folded clothing for retail. OPP gives the "new stock" look on a shelf or inside a mailing bag. Our listing suggests 10 x 14" to 14 x 17" for folded T-shirts and light garments, and 15 x 20" and 18 x 22" for bulkier folded clothing.
- Craft and handmade products. Clear presentation for small items sold at markets or online.
- Inner packaging. Inside a mailing bag or box, an OPP bag keeps the product clean and presentable.
OPP's stiffness is an advantage for flat items, because the bag holds its shape and looks neat. It is a disadvantage for bulky or irregular items, which can make the film crease and look untidy, and for sharp corners, which can nick the film and start a tear.
Where polythene bags work best
- Bulky soft goods. Bedding, cushions and large folded items fit more easily in a soft, flexible bag. Our largest size, 36 x 48" (914 x 1219mm) in 200 gauge, suits items such as bedding.
- Storage and dust protection. Covering stock, furniture parts or equipment in storage.
- Long, narrow items. Our 12 x 24" (305 x 610mm) size suits long, narrow parts.
- Warehouse and trade use. Bagging parts and components, lining boxes, keeping items together, where appearance matters less than practicality.
- Heavier items. A thicker gauge gives more resistance to tearing and puncture for heavier contents.
Polythene is less glossy than OPP, so it gives a more utilitarian look. For retail display of flat items, OPP usually presents better.
Thickness and gauge explained
In the UK, polythene thickness is often given in gauge. Gauge is a unit of film thickness, and a higher gauge means a thicker film. By definition 100 gauge is one thousandth of an inch, about 25.4 microns, which is why suppliers often use the approximation "divide the gauge by 4 to get microns". So 100 gauge is roughly 25 microns, 150 gauge roughly 38 microns and 200 gauge roughly 51 microns. These are approximate conversions; use the supplier's stated specification where precision matters.
Our clear polythene bags come in three thicknesses, depending on the size:
| Gauge | Approximate thickness | Our listing's guidance |
|---|---|---|
| 100 gauge | About 25 microns | Thinnest; light items and dust covers |
| 150 gauge | About 38 microns | Middle option |
| 200 gauge | About 51 microns | Thickest; heavier items |
Thickness is one specification, not a full measure of strength. Bag construction, the quality of the seals and the type of polythene also affect how a bag performs. Test a bag with your heaviest typical item before ordering in bulk.
Current size, gauge and box combinations for our clear polythene bags are:
| Size | Gauge | Box quantity |
|---|---|---|
| 12 x 24" (305 x 610mm) | 200 | 500 |
| 16 x 32" (405 x 815mm) | 100 | 500 |
| 20 x 34" (508 x 864mm) | 150 | 500 |
| 24 x 36" (609 x 914mm) | 100 | 500 or 1000 |
| 24 x 36" (609 x 914mm) | 200 | 250 |
| 25 x 36" (635 x 914mm) | 100 | 500 |
| 36 x 48" (914 x 1219mm) | 200 | 100 or 250 |
View clear polythene bag sizes
Choosing the size
Bag sizes are given as width x length. To choose:
- Measure the item as it will be packed: width, length and thickness.
- Add room for the thickness. A flat bag has to go around the item, so thickness uses up both width and length. As a rough guide, add the item's thickness to both measurements.
- Add room to close. Allow extra length for folding, taping or sealing the open end.
- Choose the nearest size up.
Illustrative example: a folded T-shirt measuring 24 x 30cm and 2cm thick. Width needed is about 24 + 2 = 26cm. Length needed is about 30 + 2 = 32cm, plus a few centimetres to close, about 35cm. The 10 x 14" OPP bag (254 x 355mm) is 25.4cm wide, which is slightly short on width, so the 12 x 15" (305 x 381mm) is the safer choice. If the shirt folds to 22 x 30cm instead, the 10 x 14" works.
For flat items like cards and prints, OPP sizes are usually chosen to match paper sizes, so the item slides in flat with a small margin.
Closing and sealing clear bags
How a clear bag is closed affects both how it looks and how well it protects. Our OPP listing describes the material, sizes and pack quantities but does not list a closure type, so check the product page or ask us before ordering if a particular closure matters to you. For polythene bags, the common methods are:
- Fold and tape. Fold the open end over once or twice and secure it with a short strip of tape. Neat, quick and suitable for most stock and storage uses. Our clear packing tape includes a narrow 24mm roll that suits small bags.
- Tuck the flap. For items that will go straight into a mailing bag or box, simply folding the excess length under the item is often enough to keep dust out.
- Knot or tie. For large polythene bags used as dust covers or for bulky soft goods, a loose knot or a tie is practical, though it looks less tidy.
- Heat sealing. Some businesses use a heat sealer to close polythene bags. If you consider this, check the sealer maker's guidance for the film type and thickness you use; we do not specify heat-sealing settings for our bags.
Whichever method you use, keep it consistent. A uniform fold and tape position makes stock look organised and speeds up packing.
Clear bags in a packing workflow
A clear bag is rarely the final packaging. It usually sits inside something else, so it is worth planning how it fits the rest of the process.
Bag stock on arrival
Many sellers bag garments, prints or small products as soon as stock arrives, rather than at the point of dispatch. Pre-bagged stock stays clean on the shelf, is quicker to pick, and only needs the outer packaging and label when an order comes in.
Label the clear bag
If you sell several sizes or variants that look similar, a small product label on the clear bag reduces picking errors. Our thermal labels on rolls include small 2 x 1" and 3 x 2" sizes intended for product, stock and barcode labels.
Choose the outer packaging
For clothing, the bagged item normally goes into an opaque grey mailing bag. For prints and cards, a board back envelope or large letter box stops bending. For bulkier or heavier items in polythene, a cardboard box is usually the right outer layer. Our guide to packaging clothes for online orders walks through the clothing workflow in detail.
Buying quantities and storage
OPP bags come in packs of 100 per size, which makes it easy to keep several sizes on hand and reorder the ones you use most. Clear polythene bags come in larger boxed quantities, from 100 to 1000 per box depending on size and gauge, which suits steady warehouse or trade use.
To decide how many to buy, count how many items per week go into each size, then use a simple reorder rule: reorder when you have about one to two weeks of stock left, adjusted for how long delivery takes. Our shipping policy sets out dispatch times and delivery options.
Store bags flat in their packs or boxes, somewhere clean, dry and out of direct sunlight. Plastic film stored in strong sunlight or heat for long periods can become brittle or discoloured, and dusty bags undo the point of using clear packaging for presentation.
Food, cosmetics and other specialist uses
Clear bags are sometimes used for food, cosmetics, medical supplies or other products with their own rules. Our product listings describe both ranges as general packaging; they do not state that the bags are certified for direct food contact or any other regulated use. If your product touches food directly, or falls under specific packaging rules, you need packaging that the supplier confirms is suitable for that purpose, with the relevant documentation.
In practice, many small businesses keep regulated products in their own compliant primary packaging, such as a sealed food pouch or a cosmetic jar, and use a clear bag only as an outer protective or presentation layer. That way the clear bag never touches the product itself. If you are unsure which applies to your products, check the rules for your sector before you choose packaging, and ask us before ordering if you need confirmation about a specific use.
Common mistakes
- Using OPP for bulky or sharp items. Stiff film creases and can tear. Use polythene or a different packaging type.
- Choosing too small a bag. Forcing an item in can split the seams. Measure thickness, not just the flat size.
- Using the thinnest gauge for heavy items. Thin film is fine for dust covers but can tear under weight.
- Treating a clear bag as shipping packaging. A clear bag protects and presents; it is not a postal container on its own. Put it inside a mailing bag or box.
- Storing bags in heat or sunlight. Plastic film can become brittle or discoloured over time in harsh conditions. Store boxes of bags somewhere cool and dry.
A worked example: one shop, two clear bags
This example is illustrative, not a real customer. A small print and stationery shop sells A5 and A4 art prints, and also stores its paper stock in a back room.
- For prints: OPP bags in 6.5 x 9" for A5 prints and 9 x 12" for A4 prints, because the glossy, crisp finish shows off the artwork and keeps it clean. Each bagged print then goes into a board back envelope for posting so it cannot bend.
- For storage: large 100 gauge polythene bags to keep dust off reams of paper and finished stock on the shelves, where appearance does not matter but flexibility and size do.
The shop does not need to choose one material; it uses each where it fits.
Disposal
Both OPP and polythene are plastics. Recycle Now's guidance on plastic bags and wrapping lists all plastic bags, except biodegradable or compostable bags, among the films accepted at plastic carrier bag collection points, and asks for them to be clean. In England, GOV.UK's Simpler Recycling guidance says plastic film packaging and plastic bags will need to be collected with household plastic recycling from 31 March 2027. Until then, kerbside arrangements vary by council. Reusing bags, for example for storage or returns, also extends their life.
Questions buyers ask
Are OPP bags the same as cellophane bags?
They are often sold as "cello" or "cellophane" bags because they look similar, but OPP is polypropylene, while traditional cellophane is made from cellulose. If the material matters to you, check the product description.
Which is clearer, OPP or polythene?
OPP is generally clearer and glossier. Polythene is clear but has a softer, less glossy appearance.
Which is stronger?
It depends what you mean by strength. Polythene is more flexible and generally more forgiving of sharp corners and heavy contents, especially in thicker gauges. OPP is stiffer but can tear once nicked.
What gauge polythene bag do I need?
Use 100 gauge for light items and dust covers, 150 gauge as a middle option, and 200 gauge for heavier items. Test with your heaviest item before buying in bulk.
Can I post items in an OPP bag on its own?
We would not recommend it. Use the OPP bag as inner packaging inside a mailing bag, envelope or box.
Do clear bags protect against knocks?
Very little. Clear film keeps out dust and light moisture and protects surfaces from scuffs, but it has no real cushioning. For anything that could break or dent, wrap it in bubble wrap or another cushioning material and pack it in a box, using the clear bag only for presentation or cleanliness.
Do your OPP bags have a self-seal strip?
Our OPP listing describes the material, sizes and pack quantities but does not list a closure type, so check the product page or contact us if you need a specific closure before ordering.
What is the largest clear bag you sell?
Our largest clear polythene bag is 36 x 48" (914 x 1219mm) in 200 gauge, in boxes of 100 or 250.
Summary
Use OPP bags when presentation matters and the item is flat or neatly folded: cards, prints, garments for retail and craft products. Use clear polythene bags for bulky, heavy or awkward items, storage and warehouse use, choosing the gauge to match the weight. Measure the item including its thickness, allow room to close the bag, decide how you will seal it, and test before ordering in bulk.
