Trin-Mix # 4: The finest of the Trin-Mixes, TrinÂ-Mix # 4 is ideal for removing light to medium contamination from tools, tooling, molds and dies. It is considered a general purpose media which can be used in a wide range of applications from texturing plastic injection molds to providing appealing finishes on exposed stainless steel and aluminum surfaces. Dimensional change of less than .001 inch can be expected.