The tissue is made from five or six layers of continuous fibres, 12 micron dia., of a low – melt, corrosion resistant glass, C –glass (ASTM C162-03) randomly dispersed across the sheet. The corrosion resistance is Acid Class 1, (DIN12116), Alkali Class 2 (DIN52322) and Hydrolytic Class 3 (DIN12111). The binder, a styrene acrylate copolymer, is compatible with all types of vinyl- ester, polyester and epoxy resins. Regina SA surface tissue is used in the inner corrosion barrier to form a resin – rich layer, and also in the exterior layer to provide resin – richness for additional weathering protection. The tissue meets the requirements of British Standard BS4994, “Design and Construction of Vessels and Tanks in Reinforced Plastics” and American Standard ASME/ANSI RPT-1-1989, “Reinforced Thermoset Plastic Corrosion Resistant Equipment”.