Abstract: A method for producing mass quantities of discrete envelope and letter assemblies in a continuous operation, each of which includes an envelope and a separate letter having a business-fold disposed within the envelope, both formed from the same single sheet of material, and enabling the producer to print a personalized letter upon the sheet prior to the formation of the envelope assembly. The highly desirable end result which is attained is that the completed letter is in a business-letter-fold and the sheet moves continuously forward as the assembly is formed, such that the salutory heading of the letter opens to view when the letter is withdrawn from the envelope, and the signatory panel is folded between the salutation panel and the intermediate portion of the letter. The method is capable of continuous operation inasmuch as each sheet continuously moves in the same direction throughout each of the steps of the method.