Air is injected into the casting of this aluminum to reduce weight and create a crater-like appearance. These foam sheets are often used for sound insulation and architectural facades. Carbide- or diamond-tipped blades are required for machining. Diamond-tipped blades will cut this material more easily and not wear down as quickly as carbide-tipped blades.

Large-cell foam is lightweight due to its low density. It’s one-third the weight of small-cell foam and about 5% the weight of solid aluminum. Since it allows some light through, you can use it to build architectural light diffusers. This foam has the appearance of an aluminum sponge.