Official Seal, 1877, experimental ink essay, green trial color plate proofs mounted on paper. Paper with pencil inscription, "Oct 6th/81, Printed with regular 3ct. U.S. Stamp ink suppose to be proof against washing with either Benzine or Soap water, BP", initials of Butler Packard who was the frame engraver responsible for lathework, each proof showing the effects of washing., Very Fine and unique, ex-Christiansen, Chesapeake. Scott No. OX1-E  Estimate $2,000 - 3,000. $0 (Image)

Official Seal, 1877, experimental ink essay, green trial color plate proof on stamp paper. Perforated and gummed, block of four, bottom pair smudged from the effects of ink testing, Very Fine and unlisted, ex-Christiansen, Chesapeake. Scott No. OX1-E  Estimate $1,000 - 1,500. $0 (Image)