Abstract: A method of measuring cell size of an open cell foam sample is provided including the step of providing an amount of a material suitable for obtaining foam sample impressions upon at least partial hardening in a vessel. A foam sample is placed on a surface of the material prior to hardening of the material. The foam sample is peeled away from the material after the material has begun to harden in order to provide a three-dimensional impression of at least a layer of the foam sample including a plurality of partial spherical impressions corresponding to cells of the foam sample. The cell size is measured by measuring a diameter of a plurality of the partial spherical impressions.