An improved screen tooling for a fiber preforming process, and a durable coating system for such tooling. The coating system comprises a surface layer of a porcelain enamel composition that is generally a borosilicate glass, and preferable contains quartz, borax, boric oxide, potassium nitrate, sodium silicofluoride, and manganese dioxide, and optionally contains titanium dioxide, antimony oxide, cobalt oxide and/or barium oxide. Preferred compositions are dependent in part on the screen tooling material. The invention also encompasses a fiber preforming process that utilizes screen tooling with the coating system.