$1 Wilson Usir Watermark

Is it possible to determine if the paper used was US or USIR by the plate #'s on the sheet?

macbearin....
YES...the paper was USIR watermark.
This is ONLY found on 22000 series...w/o ARROWS

To clarify, the paper is either unwatermarked, or USIR. So, any letter showing makes it the scarce variety.

According to the United States Specialist, July 1984, "The stamps were all printed from plates without arrows and only occur in the 22 M plate number combinations." Hope this helps. Also, you may want to find a copy of "The Prexies", also by Roland Rustad.

Jack Kelley

It should also be noted that the watermark is not an especially strong one, so holding a stamp up to strong light will not always work. It really must be dipped.
And the 22000 series has to be for both plate numbers.

If you're asking whether any plate numbers were EXCLUSIVELY used for the USIR watermarked varieties, the answer is no. You can safely eliminate any item with a plate number starting with a 24 or 25 (in either color,) but you can't conclusively identify any Scott 832b by plate numbers starting with 22. Every possible combo of Scott 832b (USIR) numbers also exist on a regular Scott 832 unwatermarked variety. So if you have a 22097-22085 combo plate, you have to watermark it.

And revcollector is right - the Scott 832b USIR watermarks are often VERY light. Not only will you not be able to see (most of) them by holding up to a strong light, you may even have trouble seeing them in fluid! Plate blocks are usually straightforward though (because of the selvage. It's always fairly easy to see watermarks in large unprinted areas.) Used singles (esp with the typical heavy oval cancellations) are much tougher.