in the reported experiments, outdoor fabrics suitable for tentage, tarpaulin, and similar uses were produced from cotton yarns reinforced with glass fiber. the experimental yarns were evaluated as filling in common warps. canvas fabrics in a weight range of 200 to 270 g/m**2 were woven. the fabrics were given a typical commercial finish for 100 cotton which included mineral dyeing and the application of a wax emulsion to impart water repellency. fabrics produced from cotton/glass filament core yarns were considerably stronger than comparable 100 cotton fabrics. the experimental fabrics also lost less strength in accelerated weathering tests glass fiber reinforced fabrics treated with a flame retardant had better flammability resistance than 100 cotton fabrics. appearance, hand, and finishing characteristics of the core yarn fabrics were similar to those of the all-cotton fabrics. 7 refs