Paper Mailing Bags

Plastic-free paper mailing bags for UK e commerce sellers — kraft postal bags with an expanding gusset and peel-and-seal closure. Part of our mailing bags range. Also called kraft mailing bags, paper postal bags, eco mailers or paper mailer bags. Supplied flat in trade packs.

Replacing a poly mailer, and what actually changes

A polythene mailer is cheap, light, waterproof and almost impossible to recycle kerbside. That last point is why most sellers are looking at paper.

A kraft paper bag does the same job for most goods, and the whole thing goes in the household paper collection with no separation. That's the switch, and for most catalogues it's straightforward.

Two honest differences to plan for.

Water. Polythene is waterproof; kraft paper is not. In practice UK parcels get damp rather than soaked, and kraft handles that — but if your product would be ruined by moisture, bag it internally or use a box.

Stretch. A poly mailer gives a little. Paper doesn't. A bag packed to its absolute limit will split at the seal rather than flex, so size up rather than forcing it.

The gusset, and the postage line it sits on

Both sizes have an expanding base gusset, so one bag takes a flat item or a bulkier one without void fill.

Be precise about what that does to postage. Royal Mail's Large Letter band allows 353 × 250mm at 25mm deep, up to 750g. The gusset on these bags expands to 25mm — which means a fully-expanded bag is at the limit, not comfortably inside it, and a packed bag always measures a fraction more than a flat one.

So the smaller bag is a Large Letter only while the gusset stays partly closed. Fill it and you are on the boundary. The larger bag exceeds the Large Letter footprint at any depth and posts as a Small Parcel.

Gauge a packed sample. If your product is close to 20mm, that measurement decides whether your postage line works.

Which size, and the A4 question

Two sizes, and the choice is usually obvious once you know one thing: the larger bag takes A4 flat; the smaller one doesn't.

If you ship printed matter, documents, lookbooks or anything on A4, that decides it. For folded clothing, accessories and small goods, the smaller bag is cheaper to buy and cheaper to post.

Measure the item flat and add for depth. A bag has no rigid shape — the gusset gives you thickness, but the flat footprint has to accommodate the item lying down.

What these suit

Clothing, knitwear and soft goods

Accessories, scarves and hosiery

Books, stationery and printed matter

Cosmetics and skincare in non-fragile packaging

Subscription boxes with soft contents

Samples, catalogues and look books

Not suitable for anything fragile, rigid and breakable, or anything that must stay dry in all conditions. Those need a box. If you need cushioning without plastic, see our paper padded bags.

Plastic-free, stated carefully

Kraft paper outer, no polythene, no bubble lining. The bag goes into household paper recycling as it is.

That last part is what matters, and it's worth being precise about why. Most "recyclable" packaging is recyclable in principle and ends up in general waste because the customer has to separate two materials and won't. A single-material bag removes the decision. That's the difference between a claim and an outcome.

For brands whose customers care about waste, a visibly plastic-free mailer does more at the doorstep than any amount of messaging on the invoice.

Buying by the pack

Supplied flat in trade packs with price breaks as quantities increase. Two sizes cover most catalogues, and both are held deep — these are among the best-stocked lines we carry, so a busy month doesn't put you on back-order.

We buy these as part of a manufacturing group, at volumes a reseller can't reach, and hold them across over 100,000 square feet of warehousing.

The Kraft face takes labels and direct print cleanly. A printed bag is one of the cheaper pieces of branding available to an online seller, and we quote on bespoke print and sizes.

Delivery and returns

Order by 2pm, Monday to Friday, for same-day dispatch. Free UK mainland delivery in 1–2 working days, with a £75 minimum order. Full terms on our delivery and returns pages.