Disclosed herein are cellulose/polysaccharide composites comprising a) cellulose; and b) an enzymatically-produced polysaccharide, certain derivatives of an enzymatically-produced polysaccharide, or a mixture thereof; wherein the enzymatically-produced polysaccharide and the polysaccharide derivative are water-insoluble. The cellulose is plant-derived. The composites are useful in forming articles such as paper, packaging material, or insulating material.