When Are Stamps Gummed On Rotary Press?

I have been trying to understand how postage stamps are produced in the USA during 1922-1956. I recently learned about the rotary press and trying to understand the process, but I don't understand when and how the gum gets placed on the stamps (in layman's words)

I read in an old magazine article there is a drying machine to dry the glue, but I don't know if its applied prior to printing, during printing but prior to the actual printing, etc.. Also does it sit in the dryer or is it passing through a dryer.

I'm also not clear when the sheets are cut and when the stamps are perforated.

Thank you

Best explanation of the production of these issues is demonstrated in, "United States Postage Stamps of the 20th Century, VOLUME 3, 1922-1935;©1935 by Max Johl, published by Lindquist Publications, Inc., New York., N.Y."

Go to the link below. Find pages 245 CHAPTER IV, MANUFACTURING and the process is explained there.

http://www.siegelauctions.com/enc/p...hl_Vol_3.pdf

Reading it now. Thank you

For the Stickney rotary press, the paper roll is wet first. Then, it is printed on and dried. Then, it is gummed and dried. Then, the gum is broken by gum breakers. Then, it is perforated and then cut into sheets and panes.

During flat press printing is the process it the same order?

Yes, it is the same for flat plate press wet printing using cut paper sheets except that there are no gum breakers and the cut printed sheets are perforated and further cut into panes by the perforators.

Another thanks, this time to Hal, for this wonderful piece of Stamp History. This Forum does have many Historians and I like it !

This is why Philathely is a great hobby .