DESIGN & FINISHING GUIDE

Designing for Cosmetic Appearance

For consumer-facing products, a flawless finish is not a luxury—it's a requirement. This guide explains the processes we use to create parts with a premium, Class-A cosmetic appearance.

What is a "Class-A" Surface?

In product design, a **Class-A surface** is any surface that is directly visible or touched by the user. These are the cosmetic surfaces where appearance and tactile feel are paramount.

Achieving a Class-A finish means creating a surface that is completely free of blemishes, tool marks, scratches, or defects. It requires a meticulous, multi-step finishing process that goes far beyond a standard machine finish.

A part with a flawless, high-gloss painted surface, representing a Class-A finish

Our Processes for Premium Finishes

1. Meticulous Sanding

The foundation of any good finish. Our skilled technicians meticulously sand the part with progressively finer grits of sandpaper to remove every trace of machine marks or 3D printing layer lines.

2. Priming & Painting

We apply high-quality automotive primers and paints in a controlled spray booth. This allows us to match any color standard (RAL/Pantone) and achieve a specific gloss level, from flat matte to high-gloss "piano black".

3. Polishing & Buffing

For a mirror-like finish on metals or optical clarity on plastics, we use a multi-stage buffing process with specialized compounds to create a flawless, highly reflective surface.

Cosmetic Finishing FAQ

How do I specify which surfaces are Class-A?

The best way is to provide a 2D drawing where you clearly mark all of the critical cosmetic surfaces. This allows us to focus the intensive finishing work only where it's needed, which is much more cost-effective than finishing every single surface of the part.

Can you simulate different material textures?

Yes. Using specialized paints and finishing techniques, we can make a plastic prototype look and feel like brushed aluminum, soft-touch rubber, carbon fiber, or wood grain. This is an excellent way to create high-fidelity appearance models before committing to the real materials.

What is the most durable cosmetic finish?

For aluminum, Type II or III anodizing provides a very hard, durable cosmetic finish. For steel and aluminum, powder coating is extremely resistant to chipping and scratching. For plastics, a high-quality automotive-grade two-part paint with a clear coat offers excellent durability.