A single web is printed in side-by-side relation with variable and non-variable information forming document and envelope web portions. The web is split longitudinally and the document web portion is cut to form discrete documents. Each document is folded about transverse foldlines to form a folded document and rotated 90.degree. for registration with matching envelope portions on the envelope web. Glue lines are applied to the envelope web. The envelope web is then plow-folded along both margins to form first and second flaps overlying and containing the document within the envelope portion of the envelope web. The glue lines are sealed to one another and excess envelope web material between adjacent envelopes is removed whereby envelopes containing documents sealed within the envelopes and forming mailers are provided.