TPE & Silicone weight

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I kind of curious, does anyone know the weight of these substances in a standard volume, i.e. 400 grams per cubic centimeter, or 4 ounces per cubic inch? I'm sure it can vary based on the specific formula, but my interest isn't exact enough to need account for slight variations, rather than just an approximate number. But it would need to be for the straight material not including foam, other materials, or air gaps.