C6

The C6 envelope has compact dimensions of 162mm x 114mm which gives it a surface area of 18,468 mm2. Its maximum enclosure size is typically around 110mm x 156mm. The C6 was created based on the ISO 216 standard that assigns envelope sizes numbers starting at C0. Specifically, the C6 gets its name from being able to hold a standard A4 sheet of paper folded into quarters widthwise - an A4 sheet measures 210mm x 297mm. When folded in quarters it becomes an A6 sheet at 105mm x 148mm which fits well into a C6 envelope. This makes the C6 a very versatile size for mailing small leaflets, flyers, postcards and invitations originating from A4 paper. The C6 is popular worldwide for both commercial and personal envelopes. Along with DL and C5 sizes, it remains one of the most ubiquitous envelope sizes globally.