A render can make any colour look right. The trouble starts when the first shots come off the tool and the “graphite grey” is warmer than expected, the matte face has shiny patches near the gate, and the logo has drifted. Good CMF design is less about picking a beautiful palette and more about choosing colours, materials and finishes that a moulder, a painter and a printer can reproduce on the 500th unit as faithfully as on the first.

This post is for founders and product teams heading towards their first production run of a connected device. It covers the decisions we lock down early, the specifications that actually reach the factory, and the finishes we steer clients away from when volumes are small.

Why renders are the wrong reference for CMF design

A render is lit by a virtual environment, with perfect surfaces and no process variation. A moulded part is lit by whatever is in the room, and its surface carries the texture of the steel, the flow of the resin and the temperature of that day’s run. Treat the render as intent, not as a specification.

The reference that matters is physical: a colour plaque in the chosen resin, with the chosen texture, viewed under controlled light. We ask for these early, because the same colour code behaves differently in PC/ABS, polypropylene and TPE. A grey that looks neutral in ABS can read slightly blue in a translucent-prone resin or slightly yellow in a material with a natural amber tint.

Colour: specify it so a factory can measure it

“Match Pantone Cool Gray 9” is a starting point, not a specification. Pantone references are printed on paper or plastic chips, and the moulder still has to formulate a colour for your resin. To make colour repeatable, the specification needs a few more things.

A physical master. An approved plaque or golden sample, signed off and kept by both sides. Every batch is compared against it, not against a screen.
Measured values and a tolerance. CIELAB values taken with a spectrophotometer, with an allowed difference expressed as ΔE. For visible housing parts, a tolerance of roughly 1.0 to 2.0 is common; tighter is possible but costs more and leads to more rejected lots.
Viewing conditions. Which illuminants the match must hold under, typically D65 daylight plus a shop or home light source. Two greys can match under one light and separate under another; this is metamerism, and it shows up most when parts in different materials sit next to each other.
The colouring method. Masterbatch added at the press is cheaper and flexible; pre-compounded colour is more consistent from batch to batch. For small runs with strict matching, pre-compounded is usually worth the minimum order.

The hardest case is a product where two materials must look identical, such as a rigid housing and an overmoulded TPE grip, or a plastic shell next to an anodised aluminium part. Different materials scatter light differently, so we either accept a deliberate contrast or budget time for several rounds of matching.

Materials that behave the same on every run

Material choice is mostly an engineering decision, but it constrains everything CMF can do. A few patterns we rely on:

PC/ABS is a dependable default for housings: good impact strength, a stable surface and predictable colour. Pure ABS is cheaper but more prone to UV yellowing if the product lives near a window or outdoors.
Polypropylene is tough and cheap but harder to paint, print or bond without surface treatment, which limits decoration options later.
Glass-filled grades give stiffness but can bring fibres to the surface, which dulls gloss and makes colour less uniform. They suit internal structure better than visible faces.
Outdoor products need UV-stabilised grades. Dark colours absorb more heat and can soften or warp parts that would be fine in a light colour.

Lot-to-lot variation in the base resin is real. Specifying a named grade from a named supplier, rather than a generic material family, removes one source of drift.

Finishes: texture, gloss and the tool

Most of the finish on a moulded part comes from the tool, not the plastic. Textures are usually specified against standard references such as VDI 3400 spark-erosion grades or Mold-Tech chemical-etch patterns, and gloss is measured in gloss units, usually at 60°. Both should appear on the drawing, per face.

Texture has geometric consequences. Deeper textures need more draft so the part releases without scuffing; a widely used rule is around 1 to 1.5 degrees of extra draft for every 0.025 mm of texture depth, but the texture supplier’s guidance for the specific pattern takes precedence. Vertical walls designed with half a degree of draft will not accept a heavy texture later without reworking the geometry.

Texture is also a forgiving finish. A fine matte texture hides sink marks, flow lines and small scratches that a high-gloss surface displays clearly. High gloss is beautiful in a render and unforgiving in production: it needs polished steel, careful processing and protective film in packaging.

Finish	Tolerance of defects	Cost and risk at small volumes
Fine matte texture	High	Low
Medium or coarse texture	High, but needs extra draft	Low
Moulded-in high gloss	Low	Medium to high
Painted or soft-touch coating	Medium, wears over time	High: extra process and yield loss

Decoration and marking that last

Logos, icons and regulatory markings are part of CMF too. Each method has a different cost profile:

Moulded-in marks cost nothing per part once the tool is cut, but changes mean modifying steel. Good for regulatory text that will not change.
Pad printing is cheap and flexible for small runs, but registration and ink adhesion need checking, especially on low-surface-energy plastics.
Laser marking is crisp and permanent on suitable resins, and the artwork can change without tooling. Contrast depends on the material and additives, so test it on the real colour.
In-mould decoration and labels give rich graphics but add tooling complexity and are rarely justified for a first batch.

Soft-touch coatings deserve a specific warning. They feel excellent on day one, but some formulations become tacky or wear through at grip points over months of use. If a soft feel is important, an overmoulded TPE is often more durable than a sprayed coating.

Where the CMF decisions belong in the schedule

CMF is easy to postpone because it feels cosmetic. In practice, texture affects draft angles, material affects wall thickness and snap fits, and decoration affects where gates and ejector pins can go. Leaving it until after the tool design is frozen is what produces expensive compromises.

We make the first CMF choices during enclosure design, alongside DFM, and confirm them with physical samples before steel is cut. Prototypes printed in SLS or machined from block are useful for fit and feel, but they do not tell you how the moulded colour and texture will look; for that you need plaques or first shots. You can see how enclosure work fits with the rest of a project on our services page.

A CMF checklist before you commit to tooling

Every visible face has a named material grade, a colour reference, a texture reference and a gloss target on the drawing.
Colour has a physical master, measured CIELAB values, a ΔE tolerance and the illuminants it must match under.
Draft on textured faces has been checked against the chosen texture depth.
Faces where two materials meet have been matched on real samples, or a deliberate contrast has been chosen.
Decoration methods have been tested on the actual resin and colour, including adhesion and abrasion.
High-gloss and coated surfaces are used only where they earn their cost and yield risk.
The approved golden sample is stored by both you and the manufacturer, and every lot is inspected against it.

None of this is glamorous, but it is the difference between a product that looks like the render and one that looks slightly different every time you reorder. If you are planning a first production batch and want a second opinion on the CMF specification, a short scoping call is a good place to start.