Surface Finish

Surface Finish – Why Polish and Etch Are Key

Surface finish can be created by either mould polishing, spark eroding, or treating mould surfaces by “etching” patterns into them. But it’s one of those elements of product design that often doesn’t get a second thought. In this post, we’ll highlight the impact that surface finish can have on a product and its quality.

What is surface finish – and Why is it important?

Surface finish affects various aspects of the design process and the user experience:

Tactile interaction
We absorb a vast amount of information through our skin and sense of touch. Materials applied to various parts of a product provide different sensations, and this can have a significant sensory impact and influence on the end user. 

Perceived quality
By breaking up the areas of a product with different surface finishes, you can create a sense of refinement and care in the design. It can also suggest more forethought was put into the product by the brand, without raising the unit price of that part.

Brand identity
Polishes and surface etches can be employed as part of a brand guide, and used across a range of products. This is noticeable when using a combination of “spattered” type surface roughness etches (or EDM finishes) and geometric etches such as dots, crosses, triangles or other custom motifs.

Hiding manufacturing defects
Lastly, polish and etch finishes can effectively hide sink marks, weld and flow lines, and other imperfections. This is perhaps the origin of the use of surface treatments.

Polish and Etch

Let’s Take A Look At An Example.

We recently worked on this two-piece construction of a toolbox handle. The main body (shown in black) fastens to the toolbox, and the outer dress piece (in red) clips into the handle body. Both parts are made of ABS plastic.

The image on the left has no specific surface finish applied. The injection moulding tool has been finished in #1000 polish, which leaves a surface that is smooth to the touch, but has no interesting characteristics. In comparison, the image on the right shows the same part after the application of various etches and polishes.

We used the following surface treatments:

  1. Highly polished branding text (shown here as TOOLBOX)
  2. Coarse surface etch surrounding the text (Mold Tech 15605)
  3. Highly polished shadow gap
  4. Geometric checker pattern etch (Mold Tech 14083)
  5. Bump pattern, applied to the black handle (Mold Tech 15080)

Contrasting polished areas with coarse areas is often enough to create that extra level of detail. The geometric etch can also be used as part of the brand guide, where it would be replicated across other products in the same range to create continuity and a strong brand identity (we’ll talk more about geometric etches and branding in another post).

So which do you prefer? While the original handle looks reasonable, once you see it with its final surface treatments, it appears simplistic and unfinished in comparison. 

In summary, it’s important to remember that creating a great product is as much about the idea and function as it is about the “finishing” touches (pun intended). Polish and etch can undoubtedly impact how well-finished, high quality and memorable your product is. Take advantage of this and how it can improve and extend your brand story.