Cut Squares, General Identification Help

Thank you very much! Trying to study and organize United States covers. Cannot find online an info about DIE identification - exact measurements. Would you help?
I can make more scans and provide with all the measurements in a minute. Thank you!

I don't know how much help I can be. I use the same stamped envelope identifier you do.
Exact die measurements? Not sure I follow, perhaps if you explained a bit what you are looking for?

I made a conclusion that DIEs are numbered in accordance to the difference in their exact measurements.
As for example: design U91 shared by Scott #s U411 (die 8)

Am I wrong? Why those DIEs are numbered?

Is it U71?
Do the heavy cancellations make it worthless?
Thank you.

Bust points between second and third notches of inner oval.. check
"G" of "POSTAGE" has a bar.. check
ear indicated by one heavy line .. ??
one vertical line at corner of mouth..check I think it is U71

The value .. that's a nice example of an ellipse cancel, so it's representive of the type. But the back shows some damage. There are lots of nice cancels on cut squares.

Thank you.

If you are a flyspecker, you may have noticed a couple attributes of this particular cut square. See the three arrows below. These three letters are filled in. The teeth in the upper left show signs of re-entry. Flyspecking this issue can be a rewarding, yet low cost, specialty. Just the thing to scratch that flyspecking itch. There are dozens of die varieties for this 2 cent green.

Thank you!

Unfortunately the Scott catalog editors identify the pictures of the various die types with a you prefix, same as they identify the actual envelopes. The number under the picture is sequential and not related to the size of the die. Die numbers for a particular type were generally assigned based on the sequence of discovery and/or issue.

Better identification information is available in the UPSS specialty catalogs, one for the 19th century and one for the 20th/21st century. http://upss.org

Well to the original poster of the thread. there is a paper sample book.
https://www.amazon.com/Stanley-Gibb..._top?ie=UTF8
they show up now and then and are a valuable resource....

L E Warda UPSS APS and MSS

Hello all.
Is it U71? I will appreciate any comments.

Yes, Scott Type U71. Die 88 in UPSS catalogs.

Thank you so much, ThomasGalloway! ))

I just had to say the pic you took of the die U71 below with the light shining thru the cut square was genious. you can see the thins and a great pic of laid paper with the diagonal pattern showing clearly. Nice Pic

@spain_1850 -- postalstationery.com has a whole section of cut stamps by their U numbers in chronological order, so you can at least attach a Scott number.

Granted, there are undoubtedly print catalogs that go into intense infinity on varieties, etc., but IMO this is a good basic reference that may be a free help especially for the "I inherited a boxful of squares and have no idea what these are" peoples.