Envelope sizes & specifications

All the technical information you need to know about specifying envelopes including envelope size chart, styles and closures.


Envelope sizes


Front view

envelope-front.JPG1. Face
2. (Top) Flap
3. Window

Back view


1. Depth                         7. Right Hand Side Seam              

2. Length                        8. Throat             

3. (Top) Flap                    9. Top Flap Crease          

4. (Depth) of Flap            10. Gum Line     

5. Back Flap                    11. Gum Area   

6. Left Hand Side Seam    12. Shoulder



the wallet.JPG

Opening along the long edge.


The Pocket.JPGOpening along the short edge.

Diamond Flap

Diamond flap.JPG

Traditionally used for greeting card envelopes.

Standard Wallet

Standard wallet.JPG

Opens along the long edge, the most common form of envelope in use today.

Constanzia Wallet

Constanzia Wallet.JPG

General construction as Standard Wallet, but with the side seams folded outside the backflap. Ideal for filling machine use

Board Backed

Board Backed.JPG

Used wherever the contents need some form of protection. Printed 'Please do not bend' in red.



Envelopes with expanding side and bottom seams and extra length flap, to take bulky items, such as catalogues.



Envelope closures

Gummed Flap

Gummed Flap.JPGThe flap has a strip of gum which must be moistened and secured down to seal.

Self Seal

Self Seal.JPGThe bottom part of the flap is folded down, as is the top part. Both parts have a strip of latex. To seal, the top and bottom parts of the flap are lifted and the top part then folded over the bottom part and pressed together to form a seal.

Superseal (Peel and Seal)

Superseal (Peel and Seal).JPGAn area of gum is applied to the flap and a silicone strip is attached. This strip is removed and the exposed gummed flap is turned down over the back of the envelope and pressed down to securely seal.