During the printing process, a number of the first sheets are left without perforations. For French issues, about 1,000 stamps are left imperforated (twenty sheets of fifty, or forty sheets of twenty-five) or 2,000 for small-sized stamps (twenty sheets of 100). Since 1941, these Imperforates have been distributed to high government officials.

Imperforates can be collected in many different forms.

Set of 4

Single Single with margin, called "Margin Copy" Pair

Some collectors may even want full sheets.