Study of Microprinting, 1992-1999, unusual display of United States postage stamps with security printing technology known as microprinting, in which words or numbers are imbedded in the design and not normally visible to the naked eye, and sometimes only visible with special viewing devices provided by the postal service. This collection has stamps with face values to $11.75, some commemoratives in sheets, all with notations by the collector as to where the imbedded characters are to be found in the design; along with list of issues from Linn's Stamp News article. Please inspect. Estimate  $100 - 150. $0