PURPOSE: To manufacture a twofold superposed collator in an easy manner, by folding a web to be printed and discharged out of a web rotary press with a sized superposed twofold collator and a chopper folder without using a former folder.

CONSTITUTION: The said web is slit by a slitter 2 in two rows in the web forward direction and, after being divided into symmetrical two sides by turn bars 7 and 7 and guided, an inner surface to be superposed to the web on one side to the web 1 on the other is sized by a sizing roller 3 along the web forward direction. And both webs are superposed with each other, passed through between nip rollers 6, and both these webs are stuck to each other at a sizing part while pressing them. Afterward, a sheetlike superposed paper sheet 4 is formed by a cutting drum 8. The said paper sheet 4 is conveyed forward by a flat belt 9 and, after contacting with the front end, it is chopped by a chopper 5 of a chopper folder along the sizing part, making it into being twofold, thus a collator is formed.