stuff vs foam

Other hyponyms of stuff include ballast, bedding, bedding material, litter, rind, recycling, precursor, atom, corpuscle, molecule, mote, particle, speck, ammunition, floc, floccule, HAZMAT, aggregate, raw material, staple, sorbate, sorbent, sorbent material, diamagnet, mineral, rock, stone, adhesive, adhesive agent, adhesive material, sealing material, animal material, fluff, bimetal, abradant, abrasive, abrasive material, chemical, chemical substance, composite material, conductor, dielectric, insulator, nonconductor, contaminant, contamination, particulate, particulate matter, dust, elastomer, earth, ground, discharge, emission, detritus, waste, waste material, waste matter, waste product, fiber, fibre, fill, filling, homogenate, humate, impregnation, paper, packing, packing material, wadding, color, coloring material, colour, colouring material, plant material, plant substance, radioactive material, thickener, thickening, toner, translucent substance, transparent substance, undercut, builder, detergent builder, vernix, vernix caseosa, wad, electroceramic material, pyroelectric material, piezoelectric material, ferromagnet, antiferromagnet.