Specifications include, but are not limited to: These stamps must be Fuson, stamps or equal consisting of a minimum of five impressions or layers, including safety tint lettering. The stamps must be suitable for positive application with heat to the receiving surface such as cellophane and polypropylene. SIZE, DESIGN AND COLORS: Each stamp is to be of irregular shape and outline and shall contain not less than three distinctive colors. Half-tones, Ben-Day effects, shades, tints, or tones of a color will not be acceptable or considered as separate and distinctive colors. The safety tint lettering shall not be considered as one of the stamp colors. tamps shall measure approximately ½" x ½”. Colors and design of stamps to be approved by the Maryland Comptroller of the Treasury. Bidder must submit with proposal, and without charge, suggested designs and colors.