Check the listing for details. Experimental "S" 1935A $1 Silver Certificate 7271C. Made in United States. Listed at 149.99 USD. Offered here is a 1935A $1 Silver Certificate featuring the scarce “S” experimental block. During the mid-1930s the Bureau of Engraving and Printing tested different paper compositions to improve the durability of U.S. currency, resulting in special experimental notes marked with distinctive block letters. Notes from these experimental runs are highly sought after by collectors due to their limited production and interesting place in U.S. currency history. This example displays the classic blue seal and serial numbers of the silver certificate series and represents a fascinating piece of American paper money experimentation. A desirable addition to any collection of U.S. currency, silver certificates, or Bureau of Engraving and Printing test issues.