Most of us are familiar with an ‘A4’ sheet of paper. The A paper series is within the ISO 216 standard, which is the international standard for paper size.
There are only a few exceptions, for example, North America and some areas of Central and South America. Here the terms ‘legal’ and ‘letter’ are used which you may have noticed in your printer settings.
The envelope sizes UK follow the C series which follow the A series of paper sizing. For example, an A4 sheet of card or paper fits a C4 envelope. The C4 envelope is larger, allowing the paper to fit inside. So paper sizes have an ‘A’ prefix where envelopes have a ‘C’ prefix.
Remember that all envelopes, including wedding envelopes, can be ‘portrait’ or ‘landscape’ with the opening edge being on the short or long side. Those opening on the long edge are ‘banker’ style, whereas those opening on the short edge are called ‘wallet’.
Envelopes can also be gummed or peel and seal both works equally just as well!
If you’re making A6 size wedding invitations, you’ll need a C6 envelope, simple really!
For a quick reference guide to envelope sizes and associated paper sizes view our envelope size charts below.