Useful Information

Envelopes are divided into two basic types

Wallet and Pocket or Bankers Envelopes

Pocket Envelopes seal on the shortest edge, Wallet Envelopes (also known as Bankers Envelopes) seal on the longest edge.

Size is always stated as Depth x Width. The width is always the seal-flap side and stated second. For example, 110 x 220mm denotes a wallet, whereas 220 x 110 denotes a pocket.

Each type has certain common terminology even if the shapes differ, such as seal-flap, seam etc. The back or reverse of an envelope is the side on which the seams are made. The other side is called the face.

Standard Envelope Sizes

Standard Envelope Sizes

C7 81mm x 114mm
C6 114mm x 162mm
C5 162mm x 229mm
C4 229mm x 324mm
C3 324mm x 458mm
C2 458mm x 648mm
C1 648mm x 917mm
C0 917mm x 1297mm
DL 110mm x 220mm

Seal Flap Types

Gummed flaps

Gummed flap envelopes need to be moistened to seal down, and are used for hand sealing as well as on automatic inserting machines.

Self-seal flaps

Self-seal envelopes have two lines of natural rubber latex, and seal on contact without the need for moistening.

Re-seal flaps

Re-seal envelopes are similiar to self-seal envelopes but can be opened and resealed as necessary, ie for customs inspection etc.

Peel and seal flaps

Peel and seal envelopes have a single line of synthetic contact adhesive which is covered by a silicone release liner paper. Removal of the liner paper allows the flap to be sealed.