GFRG stands for Glass-Fiber Reinforced Gypsum. It's also called GRG or FRG. GFRG is a material similar to drywall - gypsum board - but stronger due to the reinforcement of glass fibers. GFRG products are made using molds, which lends itself very well to creating curves, unique shapes, and clean, crisp edges and reveals. It's used often in combination with drywall because it can be taped and sanded just like sheetrock to remove joint lines.