Fred Thompson's 'Thompson Art Company' made miniature pin trays with brass handles. Miniature pin trays were usually 3.5 inches wide by 2.5 inches high. The Thompson Art Company relied on the 'TACO' lable printed on the back dust cover for identification. But when the dust cover deteriorated or fell off identification was a little more difficult. On some miniature pin trays a copyright mark can be found in the lower left corner of the photograph. This was one method the Thompson Art Company used to copyright their work. For a visiual on The Thompson Art Company's use of TACO lables and the copyright mark see "TACO Nature Studies Lable"