Mailing Bags

Postal Mailing Bags for Business and E-commerce Dispatch

Mailing bags, also called postage bags or postal bags, are lightweight postal packaging used to send clothing, textiles, books, accessories and other soft or flat products. They are available in plastic and paper options, with different styles suited to privacy, product visibility, branding and sustainability requirements.

Packaging Express supplies four types: grey, coloured, clear and kraft paper. All have a peel-and-seal self-adhesive strip, which closes the bag in one action and leaves a tamper-evident seal without tape.

For many soft or flat products, a mailing bag is a cost-effective alternative to rigid packaging because it adds little weight to the parcel. The sections below explain how the four types differ and which products each one suits.

Mailing Bags

Mailing bags sit at the lighter end of parcel packaging, alongside padded envelopes and small cartons. They are used by online retailers, marketplace sellers, subscription services and marketing departments, and by anyone posting soft goods in volume. They protect contents from water and dirt, store flat until needed, and conceal what is inside where the bag is opaque.

What a mailing bag does not do is resist crushing. Anything fragile, rigid or awkwardly shaped needs rigid parcel packaging such as a cardboard box, and anything breakable inside a bag needs protective packaging wrapped around it first.

Plastic mailing bags are made from LDPE, with kraft paper as the paper-based alternative across the range.

Types of Mailing Bags

Grey mailing bags

Grey mailing bags are the low-cost, lightweight everyday option, described by Packaging Express as an e-commerce essential. They are an own-brand product designed to keep postage and packing costs down, and they are available in over 20 sizes, which is the widest size choice in the range, so there is usually a postage bag to fit without excess material.

Choose grey where the priority is cost per bag and having a size that fits the product, particularly if you post a wide range of product sizes.

Coloured mailing bags

Coloured mailing bags are made from thick, high-quality coloured polythene that is burst, water and tear resistant, giving a professional finish on arrival. They are opaque, and the peel-and-seal lip is permanent, with a 40mm diameter.

Available in multiple colours and sizes. Choose them where packaging is part of how the brand presents itself, or where the bag itself needs to hold up in transit rather than simply contain the product.

Clear mailing bags

Clear mailing bags are see-through polythene, 30 microns thick, with a permanent 40mm peel-and-seal lip and a printed child safety notice. Packaging Express states that the printed warning makes them compliant with the packaging terms and conditions used by various marketplaces and platforms and removes the need to apply separate suffocation labels.

Choose clear where the contents need to stay visible: for picking and checking in a warehouse, for retail display, or where the product itself is what the customer should see first. Where privacy matters, an opaque grey or coloured bag is the better fit.

Kraft paper mailing bags

Kraft paper mailing bags are made from strong, durable 130gsm kraft paper and are designed to take light, medium and heavy-duty items. The bottom of the bag is expandable, giving a deeper base and wider opening than other mailing bags and envelopes, which makes bulkier items easier to pack. The peel-and-seal strip is 40mm.

Choose kraft where you are moving away from plastic packaging, where customers expect paper, or where the product is too deep to sit flat in a standard bag. The sustainability section below covers what Packaging Express states about disposal.

Choosing the Right Mailing Bag

Four things decide it: what you are sending, whether it should be visible, how it needs to be disposed of, and what size it is.

What is the product?

Soft goods such as clothing and textiles sit well in any bag. Books and printed matter suit paper or plastic equally. Anything rigid, fragile or with sharp corners should go in a box or a padded envelope rather than a mailing bag.

Should the contents be visible?

Clear bags show the product. Grey and coloured bags are opaque and conceal it. This is often the deciding question, and it usually comes down to whether the bag is being picked and checked internally or posted straight to a customer.

Plastic or paper?

Kraft paper is the option to specify when the disposal route matters. Plastic bags are thinner, more flexible and available in a wider size and colour choice.

What size?

The postage bag should fit the product without a lot of loose material. Too small and the seal is under tension; too large and the parcel arrives looking untidy. If your products vary a lot, the grey range's 20-plus sizes give the most room to match bag to product.

Two further points. If colour is part of your brand presentation, the coloured range is the only one that offers it. If your products are deep rather than flat, the expandable base on the kraft bags handles bulk better than a flat plastic bag.

Choose at a glance

• Grey mailing bags. A lightweight everyday postal bag for general products, with the widest size choice.
• Coloured mailing bags. An opaque bag in a choice of colours, made from burst, water and tear resistant polythene.
• Clear mailing bags. Where the contents need to remain visible, particularly fashion and promotional material.
• Kraft paper mailing bags. Where you want a paper-based option with an expandable base for deeper products.

Mailing Bags Compared

Postage Bags for E-commerce and Online Retail

For most online retailers, mailing bags and boxes together cover the bulk of their parcel packaging. Common e-commerce uses across the range include clothing and fashion items, accessories, books, brochures, magazines, flyers, booklets and other lightweight products.

Two practical points for anyone packing in volume:

Keep your size range tight. Where possible, choose a small number of sizes that cover the majority of your products. This can make stock management and packing more straightforward.

Protect the product, not just the parcel. A mailing bag keeps water and dirt out. It does not absorb impact. Anything that could be damaged by a knock needs bubble wrap, foam or a bubble pouch inside the bag, or a box instead.

Mailing bags for clothing and fashion

Clothing is a common use for mailing bags. Clear bags work here because garments can be identified without opening the bag, which helps with picking, packing and returns handling, and lets the product be seen on arrival. Where individual items need bagging before they go into the mailer, clear polythene bags and grip seal bags cover that job.

The safety warning matters in this context. Any clear polythene bag large enough to fit over a child's head carries a suffocation risk, which is why many online marketplaces require a printed warning on bags of this kind.

Where privacy is the priority instead, for underwear, personal items or anything a customer would not want visible on a doorstep, an opaque grey or coloured bag is the right choice.

Mailing bags and parcel packaging for businesses

Parcel packaging affects how long each order takes to pack, what it costs to send, and what the customer sees on arrival.

Presentation and privacy. Coloured bags carry brand colour through to the doorstep. Opaque bags keep contents private. Clear bags do the opposite, which is useful internally and in some retail contexts.

Plastic or paper. This is increasingly a customer-facing decision rather than an operational one. Kraft offers a paper route with a clear disposal message. Plastic offers a wider size and colour range.

If you are ordering for a business for the first time, it is worth ordering a small quantity of two or three candidate sizes and packing a real order in each before committing to volume.

Mailing bags and sustainable packaging

The clearest distinction across the range is between the plastic bags and the kraft paper bags.

Kraft paper mailing bags are described by Packaging Express as compostable, recyclable and biodegradable, and are the option to specify when the disposal route matters to you or your customers. Disposal routes differ by local authority and collection type, so check the product page for current guidance before advising customers how to dispose of them.

Plastic mailing bags in the grey, coloured and clear ranges are made from LDPE. They are not described as compostable or biodegradable, and those claims should not be transferred from the kraft range. Where plastic is the practical choice, match the bag size to the product so less material is used per parcel, and reuse bags where condition allows, for instance for returns.

Three terms that are often confused and are not interchangeable:

• Recyclable means the material can be reprocessed, provided it reaches the right collection stream.
• Biodegradable means the material breaks down through biological action, at a rate that varies by material and conditions.
• Compostable means it breaks down into compost under defined conditions.

Frequently Asked Questions

What are mailing bags used for?

Posting products that do not need the rigid protection of a box: clothing, textiles, accessories, books, brochures and other flat or soft items.

Are mailing bags cheaper than boxes?

For many soft or flat products, mailing bags can be a cost-effective alternative to rigid packaging, because they add little weight to the parcel. Whether that means lower postage depends on the product, the service and the rates you are on.

Are mailing bags suitable for e-commerce?

Yes. Mailing bags are commonly used in online retail for soft and flat goods, particularly clothing, accessories, books and printed matter.

Are coloured mailing bags water resistant?

The polythene is described as burst, water and tear resistant, which helps protect contents against damp and rough handling in transit.

What are clear mailing bags used for?

Fashion items such as jeans, t-shirts, polo shirts, socks and dresses, and marketing materials such as brochures, magazines, flyers and booklets.

Why do clear mailing bags have a printed safety warning?

A clear polythene bag presents a suffocation risk to young children, and many online marketplaces require a printed warning on bags of this type. Having it printed on the bag removes the need for separate suffocation labels.

Which mailing bag should I use for clothing?

Clear bags where you want the garment visible, which suits picking, checking and retail display. Grey or coloured bags where the contents should stay private. Kraft paper where you want a paper-based option.

Are kraft paper mailing bags recyclable, biodegradable and compostable?

Packaging Express describes them as all three. They are made from 130gsm kraft paper with an expandable base and a 40mm peel-and-seal strip. Check the product page for current disposal guidance.

Do mailing bags have a peel-and-seal strip?

Yes, across all four types. The strip seals the bag without tape and leaves a tamper-evident close, so interference is visible before the parcel is opened.

What sizes of mailing bags are available?

The grey range alone runs to over 20 sizes, with further options across the coloured, clear and kraft ranges. Check the individual product pages for the sizes currently listed.

Can mailing bags be used for promotional materials?

Yes. Clear bags are widely used by the marketing industry for brochures, magazines, flyers and booklets, since the material can be seen without the bag being opened.

When should I use a box instead of a mailing bag?

When the contents are fragile, rigid, heavy or awkwardly shaped. A mailing bag protects against water and dirt but not against crushing, so anything that needs structural protection should go in a box with protective packaging around it.

Buy mailing bags and postage bags online

We supply mailing bags UK wide, from single packs for occasional post through to bulk orders for businesses dispatching every day. The grey, coloured, clear and kraft paper ranges are all available online, with sizes listed on each product page so you can match the bag to what you are sending before you order.

Still not sure which mailing bags you need?

Tell us what you are sending, roughly how many you dispatch in a typical week, and whether the contents need to be visible or hidden. Our team can help you compare sizes, materials and colours, and advise on whether a bag, a padded envelope or a box is the right format.

Call the customer helpline on 0345 224 3691, request a call back, or use the Contact Us form.