Why a Small Glossy Spot on a Silicone Cover Matters—and How We Fix It
A customer recently sent us photos of a silicone protective cover we made for a speaker. Most of the cover had a consistent EDM spark texture, but one small area on the side was noticeably glossy. The customer asked if we could improve it because the texture didn’t match. (Chicarubber)
They were right to ask. In silicone products, this kind of inconsistent gloss—where some areas are shiny and others are matte—is often called a “two-tone” finish, or a “yin-yang” surface. Even when it’s small, it’s not acceptable.
Why it happened
The cover has a complex shape, and the side has a slight undercut. Because of that, our mold maker used EDM (electrical discharge machining) for the entire mold surface. The whole surface was supposed to have an EDM spark texture. However, one small section on the side did not receive the EDM texture, so it came out glossy.
Why we can’t just cover it up
For silicone rubber parts, the surface sheen—glossy or matte—is 100% determined by the mold surface finish. That means most surface issues can be solved by improving the mold. This product will also receive an anti-dust oil coating, but that coating still won’t hide the glossy area. The real fix has to happen at the mold.
How we fix it
The mold was built last year, so we need to locate the original copper EDM electrode and perform a dedicated EDM touch-up on that small area. The goal is to match the surrounding texture exactly.
Even though it’s only a small spot on the edge, we still treat it as a quality issue. We have to look at it from the customer’s perspective. A small detail we miss can become a problem for our customer’s product.
Our commitment
At our factory, we believe surface quality is not a minor detail. It affects how the product looks in photos, on the shelf, and in the customer’s hands. When there’s a gloss or texture issue, we solve it at the source—the mold—not just try to cover it up. (Chicarubber)
Need custom silicone covers or silicone parts with consistent surface texture? Contact us. We’ll help you get the finish right.
Why a Small Glossy Spot on a Silicone Cover Matters—and How We Fix It
If you need to customize silicone products, please contact us at chicarubber
