It was now 1933 and the Secretary of the Treasury changed so the Series changed to 1928-B to accommodate the new signature. Plus the BEP continued to see if by changing the paper they could get circulating currency to last longer. So like the 1928-A Series some of the 1928-B $1 notes were printed on different types of paper. As before the differences were the relative amounts of linen and cotton paper fibers. And as before the X-B and Y-B groups were on two different experimental papers and the Z-B group was the control printed on the regular paper. Again the differences are not obvious to the eye. They can only be told apart by the block designators (X-B, Y-B & Z-B) and serial numbers. The test notes I'm posting show significant circulation but that was the purpose of the test. They were released in early 1933. 1928-B normal issue. Here is the test group. 1928-B $1 X-B block on experimental paper. 1928-B $1 Y-B block on experimental paper. 1928-B $1 Z-B block on regular paper. Their values are a bit higher than the 1928-A test set. Again for me it was a matter of finding one of each.
