Use this envelope with any 1099-MISC and 1099-R 2-up forms, from anywhere! Due to the 1099-MISC format change in 2001, use this envelope instead of the traditional 3-up envelope. The security tint and cellophane windows ensure the privacy of information. This envelope is 5 ¾” x 8 ¾”. All 1099 envelopes are constructed of 24# envelope stock.