1935A $1 Silver Certs

Late-Finished BP #470

Series of 1935A $1 Silver Certificates with back plate 470 are the rarest of the late-finished plate varieties. One dollar back 470 was a micro-era plate begun September 1, 1936, that was certified on May 13, 1943, during the macro plate era. Surprisingly, it had intermediate-size plate serial numbers—smaller than macros yet larger than micros. Back 470 likely was a $1 master back plate used for making other $1 backs.

$1 Backplate #470 Proof

Image courtesy of Jamie Yakes

Back 470 was used from May 15 to June 18, 1943, and shared press time with $1 backs having plate serials from about 2850 to 3300. From it were printed 200,225 sheets, or 2.4 million notes (not all used due to spoilage). All received Series of 1935A $1 faces. Active serial number blocks when back 470 sheets were available included the I-C block, numbered April 24-May 27; J-C block, May 27-June 24; and K-C block, June 24-September 18. Stars also were possibly printed at the time. Back 470 notes have proven exceedingly hard to find and only a few are reported: one from the J-C block and the rest from the K-C block.

About intermediate-size plate serials

Intermediate-size plate serial numbers (PSNs) are uncommon and have occasionally appeared on small-size plates (others are Series of 1934B $5 New York face plate 212, and $1 backs 1821 and 106 used, respectively, on Series 1974 and 1988A notes). They occurred when an operator responsible for scribing PSNs into plates used an incorrect reduction setting on a pantograph machine. A pantograph reduces traced elements, such as numbers or letters, from a template onto a substrate. The substrate in this case was the intaglio plate, which, after the initial steps of production, had no PSNs. PSNs—also called plate check numbers—were later acid-etched before the plate was finished for certification.

To do so an operator mounted an intaglio plate on the table of a pantograph machine and coated the plate with a thin layer of tar emulsion. The emulsion protected all parts of the plate not meant to be scribed and etched. The operator traced the PSN from a guide, which the pantograph transferred in reduced size through the emulsion onto a few subjects on the plate. Acid was dripped onto each PSN and an electrode was attached to the wet surface. Current was applied and the PSN was quickly etched into the exposed metal. The emulsion was removed with solvent and the plate was cleaned and polished. A proof was then lifted from the plate, checked to be free from errors, and certified by the BEP Director. The plate was ready for use and sent to the plate vault.

We cannot know exactly what caused the use of intermediate-size PSNs on back 470, but confusion may have played a part. All late-finished plates were begun when micro plate serials were standard (before 1938) but finished when macro serials were being used. Micros were approximately 0.6 millimeters tall, and macros were about 1 millimeter. Intermediates, obviously, were in between those sizes. The only late-finished plate certified with a PSN in size true to its contemporaries was $5 back plate 637. Twenty-dollar back 204 was also begun during the micro era yet finished and certified with a macro PSN. The late
finished faces—$10 faces 86 and 87, $5 face 307, and the $5 and $10 FRN faces—were certified as 1934A faces and so finished with macro size PSNs (which was normal for 1934As).

There was another, lesser-known late-finished plate with a story like $1 back 470. Series of 1928B $5 United States Note face plate 147 was started in 1936 and certified in 1943. It also was finished with intermediate-size PSNs, but never sent to press.

Written by Jamie Yakes