Envelope size guide
Known as the ISO C series, these are standard industry envelope sizes designed to accommodate standard ISO A size papers. This guide shows finished envelope sizes in millimeters.
|C6||114 x 162||Use with A6 (¼ A4)|
|DL||110 x 220||Use with DL (1/3 A4)|
|C5||162 x 229||Use with A5 (½ A4)|
|C4||229 x 324||Use with A4|
|C3||324 x 458||Use with A3|