Rotary Press Waste Stamps

HELLO
I'm new to collecting because I have the opportunity to view a very maticulate collection of commemoratives from 1893 to 1980.In thic collection is the 2 cent harding nh.i have compared the ferf and gauged them.They are ferf 11.Itook 4 of each flat plate and 4 rotary press mint nh and compared through magnification the backs and the glue patterns.There is a difference in flat plate and rotary glue patterns.I also studied the ink and under close magnification the inks are different.The flat plate has a beaded effect and the rotary press is denser and without breaks that look like beading.Can you identify a rotary waste stamp by the back of the stamp.In other words this stamp is a perf 11 but was it made on a rotary press.Any thoughts on this would be greatly app.
ALWAYS YOUNG THANK YOU

Welcome mphelan48

I think if you post this in the proper topic you may get an answer. I'm afraid I do not know enough about US stamps to answer you.

Dianne

THANK YOU DIANE

the gum on a flat plate will be smooth....
the gum on a rotary plate would have ridges....

Flat plate stamps generally, though not necessarily always, will show some ink off-set from the next sheet being staked on top of the previous sheet before the ink has completely dried on that sheet. The ink off-set will be under the gum and can be from a few tiny specks/dots to larger ink off-setting depending upon how much wet ink was present on the sheet a second sheet was stacked on top of. Rotary press stamps will not show any off-set ink on the back. As implied, the rotary waste stamp was from rotary press printing.

These stamps are usually a combination of rotary press printed stamps especially their larger design size with the perforation 11 of flat plate stamps. Thus, if I were looking for Scott # 613, I would get a copy of both # 610 and # 612 since # 613 is like a combination of some aspects of both # 610 and # 612.

I know they started adding the gum breakers shortly before the rotary Harding (612). Did all the 612s (and so the 613s) get breakers? There are no known mint 613s, but if there were... is that what the OP is asking?