The design was drawn onto a litho stone
, etched with acid, transferred to the machine stone, further treated and eventually washed with water and transferred to the printing press.
Peter McCue who had in his possession a litho stone
used in the printing of original nursing licenses when it was known as "The Colorado State Board of Nursing Examiners.
Below, Stamp fit for the Queen: The facsimile four rappen Zurich local tax stamp of 1843, resurrected by WSP, using a 19th century litho stone
press and its original techniques to present to the Queen when she visited the firm's stand at the London 1980 International Stamp Exhibition.