1935H Key To Series $1 Blue Seal Silver Certificate Key To Series Grades Choice AU/BU Slider. FR-1618 Granahan-Dillon Key To Series Out of About 22 Billion Series of 1935 Notes Printed only about 30 Million Were 1935H Making the 1935H the Lowest Mintage In The Series andThe Absolute key to the series. Silver Certificates were redeemable in Silver. One of their most distinctive qualities is the blue Treasury seal and serial numbers. These notes include an additional legend printed on the face that is not present on any other Federal Reserve notes. The legend states that Silver had been deposited in the Treasury and was payable on demand to the note’s bearer.