Base molds for use in histology feature smooth interior finishes and rounded corners to facilitate specimen removal. These molds are disposable or reusable, fabricated from specially formulated plastic or stainless steel, and certain models have wings to ensure level embedding. They are designed for use with tissue-processing/embedding cassettes, and disposable base molds are designed for zero flash. Molded for a tight fit around contained cassettes, these molds prevent excess paraffin from adhering to the sides of the cassette.