The 10 Booklet envelope has a width of 12.625 inches and a height of 9.5 inches, giving it a total surface area of 119.94 square inches. Its maximum enclosure size is 9.25 x 12.375 inches. This booklet envelope is sometimes referred to as the 10 catalog envelope.
Booklet envelopes like the 10 get their sizing from the height in inches rather than a numbering system. As the largest common booklet size, the 10 booklet provides substantial width and height for enveloping big flat pieces. Its open side seam allows easy insertion of oversized documents, posters, calendars and other large products without folding or creasing. The 10 booklet's expansive size makes it ideal for mailings needing maximum capacity for flat items. It offers efficient protection and mailing for particularly big catalogs, magazines and documents.