Specifications include, but are not limited to:. This specification covers flexible white and colored reflective sheeting in roll and cut-to-size sheets, as well as related processing materials designed to enhance nighttime visibility of traffic control signs and objects. The sheeting shall have a pre-coated adhesive protected by an easily removable liner. All sheeting shall conform to the latest version of ASTM D4956-09 except as noted within.. Retroreflective sheeting shall consist of white or colored sheeting having a smooth outer surface that essentially has the property of a retroreflector over its entire surface. Retroreflective sheeting shall be classified as follows: 3.1.1 Type I: A retroreflective sheeting commonly referred to as "engineering grade" and typically enclosed lens glass-bead sheeting. 3.1.1.1 Type I Sheeting: Minimum Coefficient of Retroreflection shall be as specified ASTM D4956-09 3.1.2 Type IV: A retroreflective sheeting that is typically unmetallized, microprismatic retroreflective element material. 3.1.2.1 Type IV Sheeting: Accelerated outdoor weathered panels exposed for 36 months and evaluated in accordance with of ASTMD4956-09 3.1.2.2 Type IV Sheeting: Sheeting processed and applied to sign blank materials in accordance with sheeting manufacturer recommendation shall perform effectively for the number of years stated in Table 7 of ASTM D 4956-09. The retroreflective sheeting shall be considered unsatisfactory if it deteriorated due to natural causes to the extent that: (1) the sign is ineffective for its intended purpose when viewed from a moving vehicle, under normal day and night driving conditions, or (2) the coefficient of the retroreflection is less than the minimum specified for that sheeting during that period listed in Table 7.