Mailing and courier bags

Designed for postal or courier transport, mailing bags are light, waterproof and have an integral adhesive strip. Courier bags are made with a 3 layer co-extruded polythene mix to ensure maximum tear resistance. Usually they are white on the outside layer and light grey on the inside layer giving them an opaque appearance, however any coloured polyethylene can be used. Polybags stocked ranges cover economy and 'Tuff' mailers, mailorder and courier bags, tamper proof, bubble and even high impact metallic advertising mailers.

Need mailing bags?

For a range of high quality mail order bags, mailing envelopes, and all types of courier sacks visit the mailing bags and courier bags section of the Polybags website, where you can buy online securely at discount prices.

Mail order bags are produced with a high quality film, designed to be lightweight but tuff. It offers excellent levels of resistance along with excellent opacity in order to keep your product safe, secure and dry through the harshest of delivery systems.

Types of bags

ISO Envelope Standards

These envelopes are widely used all over the world. The C series was designed to accommodate ISO A paper sizes. For example, a C5 envelope will accommodate an A5 sheet flat or an A4 folded once. The B series is an alternative, and is much less common than the C series. The sizes are provided in millimeters and in inches (for reference).

 Name  Size, mm  Size, in  Content Format and Comments
 C3  324 x 458  12 3/4 x 18 A3 sheet; Not very common
 B4  250 x 353  9 7/8 x 13 7/8 C4 envelope
 C4  229 x 324  9 x 12 3/4 A4 sheet; Very common
 B5  176 x 250  7 x 9 7/8 C5 envelope
 C5  162 x 229  6 3/8 x 9 A4 folded once = A5; Very common
 B6  125 x 176  5 x 7 A4 folded in quarters; Very common
 C6  114 x 162  4 1/2 x 6 3/8 A4 folded in quarters; Very common
 DL  110 x 220  4 1/4 x 8 3/4 A4 sheet folded in thirds, A5 sheet folded in half lengthwise; Very common
 C6/C5  114 x 229  4 1/2 x 9 A4 sheet folded in thirds; Common
 C7/6  81 x 162  3 1/4 x 6 3/8 A5 sheet folded in thirds; Uncommon
 C7  81 x 114  3 1/4 x 4 1/2 A5 sheet folded in quarters; Uncommon

More on packaging?

At you can find more information and articles on mailing bags and courier bags.

For more information and a list of handy resources on mail-order envelope products such as plastic mailers and mailing bags, please read mailing bags at