Bio-Foam Test Impression Foam is a closed-cell, low-density impression foam that produces a detailed reproduction of a shoe or other surface. The impression foam accurately records wear patterns and surface defects making it ideal for three-dimensional evidence test impressions. Simply impress the footwear into the foam and carefully remove. Cast-PRO Dental Stone may be poured into the test impression. A soft brush and running water should be used to scrub the Bio-Foam from the dental stone test impression. Bio-Foam Test Impression Foam is available as a single slab or single slab case.