C Envelope Formats
Published by Rosie on March 31st, 2011 in Envelopes
Being assigned the task of buying in the offices envelopes is not a nice chore when you don’t fully understand the sizes. The consequences of making a mistake can be catastrophic as a business relies heavily on its outbound mail for both invoices and sales purposes. So if that’s you, then good luck, or if you a spare moment, read on. This post will give you a simple explanation as to the different envelope formats available, their measurements and which paper fits inside them unfolded. Once you fully understand paper formats, it does make comprehending envelope formats a lot easier as they go hand in hand.
- C4 Envelopes – In basic, C4 envelopes are made to complement A4 paper, as a sheet of A4 paper will fit perfectly UNFOLDED inside a C4 format envelope. These are particularly useful for when the contents of the envelope must not be folded and must remain pristine. Dimensions – 324mm x 229mm (12¾” x 9″).
- C5 Envelopes – These are intended to be used with A5 paper UNFOLDED or alternatively with A4 format paper FOLDED ONCE. These too are a very popular envelope style and commonly contain leaflets and small brochures. Dimensions – 229mm x 162mm (9″x 6⅜”).
- C6 Envelopes – These are designed to work with A6 format paper (see the pattern here?) UNFOLDED, or alternatively with A5 format paper FOLDED ONCE, or A4 format paper FOLDED TWISE. These have many uses however most commonly are used to issue wages and payslips. Dimensions – 114mm x 162mm (4½” x 6⅜”).
- DL Envelopes – The most popular business envelope is the DL format envelope. This takes a sheet of A4 format paper folded TWISE into thirds or A5 paper FOLDED ONCE. There’s an art to folding paper for use in DL envelopes, carefully bend the letter without actually folding it into an ‘S’ shape, adjusting it until the three sections look the same size. To be extra cautious, check it against the envelope to make sure it will fit. Once you have found your three equal parts press down to a permanent fold and you’re done. Dimensions – 110mm x 220mm (4⅓” x 8⅔”).
Now that you’ve found the right format envelope you will now have a choice of seal and style. Wallet and banker variety envelopes will have the opening along the long edge and are probably the most popular envelope type. Alternatively, pocket envelopes have an opening along the short edge, these too are a relatively popular choice. Other choices include gusset which expand to hold their contents, or padded and protective envelopes which are reinforced by means of board, foam or bubble wrap.
When it comes to the seal, you have three choices. The oldest is of course gummed where the flap must be moistened in order for the adhesive to work. These are great if you don’t mind the taste, or have a wet sponge to hand, as they are the cheapest option. Alternatively, we have press and seal envelopes which simply require you to apply the two glued flapped together. Finally, peel and seal envelopes have a glued strip protected by plastic, simply fill the envelope, then peel back the plastic strip and close.


















