A bag instead of a carton
A mailing bag is the postal pack for soft, light goods. Clothing, textiles and other items that can flex belong in a bag. Anything that must keep its shape, or that has a hard corner, belongs in a box. The postal category lists mailing bags next to postal boxes, tubes, document wallets and scales.
The mailing bags category describes grey polythene bags and coloured bags. It says they are also known as shoe bags or grey mailers, and that they are fully opaque so the items cannot be seen through the material in transit.
Material
The category says these mailing bags are European manufactured, using a blend of recycled film, and that they are 100% recyclable. That is the claim to use when you are comparing them with a plain virgin-film bag or with a cardboard box. It does not make the bag a rigid pack.
PayPal branded mailing bags are listed separately, in three sizes: 250 x 350 mm, 305 x 405 mm and 425 x 600 mm. The grey range is the unbranded equivalent.
Bags that are not mailing bags
Grip seal bags, food bags, refuse sacks and carrier bags are in the polythene category. They are not postal mailers. Jiffy bubble envelopes are lined postal bags in the papers range. Document enclosed wallets are for the paperwork on the outside of a pack, not for the goods.
If you are unsure, put a sample item in the bag size you think you need. If the seam is strained or a corner sticks out, move up a size or switch to a box.
Dispatch
Mailing bags can go on the same order as labels, tape and any boxes you still need. Orders placed by 3pm are dispatched the same day. UK delivery is free on orders over £50 ex VAT.