Turner Proof Type Rc in Green, “Duthie Patent” — SOLD

Trial color proof of tye 10¢ Type R imprint in green with vertical tan lines. Turner describes the lines as gray but they are indeed tan.

This is an experimental proof, a prototype of James Duthie’s method for preventing reuse patented in 1872. Duthie was an engraver who later became the manager of the American Phototype Company. His patent called for printing the colored lines with writing ink. Attempting to alter the writing on a document using ink eradicator (e.g., to erase a pen cancel on the stamp) would also dissolve the lines and show evidence of tampering.