Fibrous sheets are coated or impregnated with a biodegradable composition to render the sheets more resistant to penetration by liquids. Biodegradable polymer blends suitable for use in coating or impregnating a fibrous sheet can be manufactured from at least one “hard” biodegradable polymer and at least one “soft” biodegradable polymer. “Hard” biopolymers typically have a glass transition temperature of at least about 10° C. “Soft” biodegradable polymers typically have a glass transition temperature less than about 0° C. Another useful biodegradable polymer composition includes one or more biodegradable polymers and sufficient inorganic filler so as to render the treated sheet microwaveable. The biodegradable polymer compositions are especially well-suited for coating or impregnating paper sheets, e.g., 12–15 lb/3000 ft2 tissue paper to yield food wraps. Food wraps will typically be manufactured to have good “dead-fold” properties so as to remain in a wrapped position and not spring back to an “unwrapped” form.