Experimental Silver Certificates

1928-A: XB, YB, ZB blocks
1928-B: XB, YB, ZB blocks
1935: AB, BB, CB blocks
1935-A: SC block red R & S
1963 CA block Gilbert test paper
1977-A EH block Natick test paper
1977-A E* block $10 Natick test paper

Yes, these are the experimentals I referenced in my questions. I'm aware that there are other non-SC experimentals, but I don't think I missed any SC experimentals.

So, the questions still stand. Anyone with any thoughts on them?

The 1928A, 1928B, and 1935 experimentals are on my radar, but have not been prioritized.

Early on, I bought the 1935A R & S notes, mostly because I thought they looked cool.
I continued with extensive research on 1963 Gilbert notes, 1977A Naticks and 1988A, 1993 and 1995 Web-Fed.

Personally speaking, I'm surprised the PM collecting community doesn't get more exciting about the extreme rarity of notes printed on Gilbert Security Paper. With only one supplier of security paper since 1861 (Crane), you would think it would be considered a big deal. After all, PAPER is the main ingredient of what we collect.

Edited to add; Concering the 1935A R & S notes, pages149 & 150 of the book Bureau of Engraving and Printing 100 Years (published 1962) references the mindset in 1944 of an experiment aimed at improving the quality of currency paper by the addition of certain chemicals during the manufacturing process. Notes with the special paper bore a small capital "S" printed in red on the face in the lower right corner adjacent to the Treasury seal. Those printed on regular paper were similarly identified with the letter "R". Approximately 1 million notes of each type were placed in circulation in June 1944. A few months later the notes began to trickle in for redemption but, unfortunately the trickle did not grow. The returns never reached a volume sufficient for making a valid analysis. Although no publicity was given, the public at large apparently was quick to observe the special markings on the notes. Rather than spend the bills, and keep them in circulation, John Q. Citizen evidently decided to retain those notes that came his way as curious.

It makes sense. If I saw an interesting note like that I'd certainly squirrel it away. I know a dollar was a bigger deal 80+ years ago, but still.

I'm not so sure it would have made a difference. From what I've read, they did get enough of the 28/28A notes back (without those big red letters, the public didn't realize there was any difference from regular notes) to do an analysis, but there aren't any records that indicate they actually did any analysis

Nice listing of the experimental issues. I'd collect them by the block for each series.

KK

I wonder what these notes were testing

They just printed the serial numbers on the paper and not the entire 3rd printing? and they only made 4 straps of notes? what could they have been testing with such a small sample size?

If I understand the COPE printing process correctly, it started with 32 note sheets, cut them into 16 note sheets, did the 3rd printing, examined and replaced (as needed) the 16 note sheets, cut the 16 note sheets into 2 note sheets, cut the 2 note sheets into single notes, gathered 100 notes into a strap, gathered 10 straps into a bundle and then 4 bundles into a brick.

If they let the machine do its work (rather than intervening with hand operations) it seems like they would have had to start with at least 100 32 note sized sheets in order to get even one strap out of the process. If they stopped the process after strapping, then they would have had 32 straps at that point, and not just 4.

There has to be more to this story