The Importance of Surface Finishes for Molded Plastic Products
Creating quality, injection-molded plastic products is more than just producing the correct shape and function. Surface finishing by carefully polishing or texturizing a mold's surface allows that finish to be transferred to the plastic molded within it. This process offers both practical and aesthetic benefits, resulting in products that look better, feel better, and work more effectively.
Appearance of Mold Finishes
Industry standard surface finishes cover a 12-grade range from a mirror-like shine to a dull, matte surface.
High-Gloss (Diamond)
The highest grades require diamond powder-polished molds which produce the smoothest, most mirror-like finishes used for optics, mirrors, and lenses.
Semi-Gloss (Paper)
Mid-grade finishes are created by using fine sandpaper to polish a mold. The results are a high-quality, smooth finish where any tooling, machining, and molding marks do not show.
Matte (Stone)
Polishing a mold with stone powder produces a dull, matte finish. This economical grade of surface finish also ensures no tooling, molding, or machining marks are visible on the finished product. Matte finishes are best suited to internal parts or those where appearance is minimally important.
Textured (Dry-Blasted)

Special textured finishes can be created by sandblasting a matte-finished mold to create anything from a fine, satin-like texture to a bumpy, stippled surface, depending on your preferences and materials.
Finishes for Functionality
Of course, plastic products don't just need to be attractive, they need to function safely and effectively — goals which can be achieved in part through surface finishes which can:
- Improve durability - Adding textured surface finishes can help prevent scuffs, scratches, or other damage in transport or display that might be visible with smoother finishes.
- Add safety - Textured finishes can make a product easier to grip or add traction and friction if needed.
- Enhance additional finishing - Some surface finishes can improve the ability of paint and labels to adhere to products.
Surface finish choices depend on your needs as well as on the mold material, part design, and the selected plastic resin. At Bennett Plastics, we have decades of experience and the expertise to help you design and manufacture the best products possible. Contact us today so we can partner with you.
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