A composition for making a cast, thermoformable sheet or slab, comprising: a syrup comprising: about 30-40% SSI—acrylic pre-polymerized syrup by weight at 20% solids; about 30-40% MMA—methyl methacrylate by weight; about 2-3% BA—Butyl acrylate by weight; about 1-15% by weight acrylic chips; and about 1-15% by weight rigid particles with a mean diameter of about 0.5-2000 μm. The rigid particles may preferably comprise a polymeric material such as poly allyl diglycol carbonate particles. A method for producing a thermoformed article having a textured surface comprising mixing the syrup as above; swelling the acrylic chips; degassing the syrup; heating the syrup; casting the syrup into a sheet; and thermoforming the cast sheet against a mold.