PURPOSE: To obtain a cured article having well-balanced lightweight and cutting properties, surface and mechanical strengths, by hot-curing a blend of an epoxy resin, specific amounts of glass microballoons, and silas balloons, and a curing agent.

CONSTITUTION: An epoxy resin having one or more epoxy groups in the molecule is incorporated with (A) glass microballoons having a specific gravity of 0.2W0.4 and a particle size ≤200μ comprising borosilicate or silica glass and (B) 10W50% by wt. based on (A) of silas balloons having a specific gravity of 0.1W0.4 and a particle size ≤600μ to give the total content of (A) and (B) of 30W60% based on the whole composition. The composition is then kneaded with a polyamine or acid anhydride type curing agent, e.g. triethylene tetramine, filled in a mold of given shape, and hot-cured. The resulting article is suitable for synthetic wood, particularly a master model, and reusable because of high scratch resistance.