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Envelope Sizes

When you've got the hang of Paper and Card sizes, Envelope sizes are pretty straightforward. They also use an ascending sequential number order which corresponds to the paper or card size; however instead of using an 'A' system, they use a 'C' system. The 'C' size will be slightly bigger than the 'A' size so that it fits snuggly inside. So with this in mind, a C5 envelope will fit a sheet of A5 paper or an A5 card blank, while a C6 envelope will fit a sheet of A6 paper or an A6 card blank – and so on. There are also special DL and square envelopes available which are corresponding sizes to DL and square card blanks. Below is a diagram showing you how the 'C' system works, plus a sizing chart containing all the measurements you'll need.

'C' System Size Chart

Size Millimetres Inches
DL 110mm x 220mm 4.33" x 8.66"
C0 917mm x 1297mm 36.1" x 51.5"
C1 648mm x 917mm 25.5" x 36.1"
C2 458mm x 648mm 18" x 25.5"
C3 324mm x 458mm 12.8" x 18"
C4 229mm x 324mm 9" x 12.8"
C5 162mm x 229mm 6.4" x 9"
C6 114mm x 162mm 4.5" x 6.4"
C7 81mm x 114mm 3.2" x 4.5"
C8 57mm x 81mm 2.2" x 3.2"
C9 40mm x 57mm 1.6" x 2.2"

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