Abstract: The invention provides a low density paperboard material and associated method for use in producing an insulated container, and is especially well-suited for making cups. The paperboard material comprises a paperboard web including wood fibers and expanded microspheres, and has a relatively low density ranging from about 6 to about 10 lb/3 MSF/mil (0.38 to about 0.64 g/cm3), a relatively high caliper ranging from about 24 to about 35 mil (609 to about 889 ?m), and an internal bond strength of at least about 80×10?3 ft-lbf (168×10?3 kj/m2), preferably at least 100×10?3 lft-lbf (210×10?3 kj/m2). For applications such as cups the material is also coated on one or both sides with a barrier coating, preferably low density polyethylene, to limit liquid penetration into the web. The low density paperboard material of the invention is convertible for manufacture of containers, particularly cups, and exhibits insulative properties comparable to higher cost materials conventionally used to make cups.