Abstract: Disclosed is a system and method for interleaved printing of letters and envelopes in an unattended manner. The system includes a memory for storing in a first portion thereof, text codes and control codes corresponding to the constant text of a form letter and envelope to be printed. As required, one or more blocks of variable data are written into the memory succeeding the form letter and envelope. The system is operative to output the contents of the memory to a printer while merging the variable data with the form letter and the envelope for a completed letter followed by the envelope. Logic is provided to utilize a selected field of a record of variable data exclusively in either the letter or envelope. The printing system is also operative to print more than one copy of the same letter before printing the envelope. All of the printing relative to the record is performed, however, before the next record is read so that distribution of the letter to all recipients can begin when the next record is read.