How to spec a color for a production run
A complete powder coat color spec names the powder manufacturer and product code, the RAL or custom color, the gloss range in 60° gloss units, the texture, and the dry film thickness in mils, and it is backed by an approved master sample. Proper Powder Coating Co. in Uintah, Utah (just outside Ogden) keeps that spec on file by part number so every production run is coated to the same standard.
Most color problems on repeat parts are not coating problems. They are spec problems. Somebody wrote “black” on the PO, the first run came back satin, the second run came back gloss, and both runs were technically black. A good powder coat color spec removes the opinions from the process. It tells the coater exactly what to buy, how to apply it, and how to check it.
If your customer will notice a shade off, so will we. Here is what goes into a spec that holds up over a long production run.
1. Manufacturer and product code
Start with the specific powder, not the color name. Every major powder manufacturer publishes a product code for each formulation: the chemistry (polyester, TGIC-free polyester, epoxy, hybrid, super-durable polyester), the color, the gloss, and the texture are all baked into that one code.
“RAL 9005 gloss” could be a dozen different powders. The product code is one powder. If you do not have a preferred manufacturer, that is fine; we can recommend one and then the code becomes the spec. The point is that it gets written down and does not change without someone deciding it should.
Also specify the chemistry if the part lives outdoors. Epoxy powders chalk and fade in sunlight. For exterior parts you want a polyester or super-durable polyester.
2. RAL or custom color
RAL Classic covers most industrial needs and is a good common language. RAL 7016 (anthracite grey), 9005 (jet black), 9010 (pure white), and 7021 (black grey) cover a large share of architectural and equipment work.
If you need a custom color, such as a brand color or a match to an existing part, you will need a physical target: a painted chip, a coated part, or a manufacturer’s custom-match panel. A Pantone number on a screen is a starting point, not a target. Custom matches take longer and usually carry a powder minimum from the manufacturer. Our custom colors and color matching page covers how that process works.
3. Gloss, in numbers
“Satin” means different things to different people. Gloss is measured with a 60° gloss meter and reported in gloss units (GU). Put a range in the spec.
| Finish | Typical 60° gloss range | Where you see it |
|---|---|---|
| Flat / matte | 5–25 GU | Architectural, furniture, equipment housings |
| Satin / semi-gloss | 30–60 GU | Railings, brackets, general fabrication |
| Gloss | 70–90 GU | Trailers, wheels, consumer products |
| High gloss | 90+ GU | Show parts, candy and clear topcoats |
Manufacturers typically publish a nominal gloss with a tolerance of roughly ±5 to ±10 GU. Using their published range is usually the simplest approach. Note that film thickness and cure affect gloss, which is one more reason to control both.
4. Texture
Smooth, fine texture, sand texture, wrinkle, hammertone, vein. Texture hides minor surface defects and handling marks, which is why so many equipment and truck accessory parts run in texture black. Texture black that stays black. It also changes how color reads, so a textured RAL 9005 and a smooth RAL 9005 will not look identical side by side. Name the texture in the spec and include it in the product code.
5. Film thickness range
Specify dry film thickness in mils, as a range. A single coat of powder is typically 2–4 mils. Two-stage systems with a primer run thicker. Too thin and you can get poor coverage or color variation on dark and bright colors. Too thick and you can get orange peel, reduced gloss, and fit problems on toleranced features.
Common spec language is something like “2.5–4.0 mils DFT, topcoat.” If you have tight-tolerance features such as bores, threads, or mating faces, call them out for masking rather than relying on thin film.
6. The master sample
Numbers get you close. A physical master sample gets you the rest of the way. There are two common forms:
- Drawdown or spray-out panel: a flat steel or aluminum panel coated with the approved powder lot at the specified film build. Easy to store, easy to compare.
- Master part: an actual coated production part, approved and kept. Better when shape and texture affect appearance.
Keep two: one for you, one for the coater. Label them with the part number, powder product code, lot number, and approval date. Store them out of sunlight.
7. First-article approval
For a new part or new color, coat one part first. Check it against the master panel for color, gloss, and texture, check film thickness with a gauge, and check masking. Then approve the run. It adds a short delay at the start of the first job and saves you from finding a problem on part four hundred.
8. Powder lots and long runs
Powder is made in batches, and each batch has a lot number. Within a single lot, color is very consistent. Between lots there is normal, small variation. On most colors it is not visible. On metallics, dark greys, deep reds, and anything next to a previously coated part, it sometimes is.
For a long run of visible parts, especially parts that get installed next to each other like railing sections or furniture sets, order enough powder from one lot to cover the whole job, plus some spare for remakes. When a new lot comes in, coat a panel and compare it to the master before production. This is the least interesting and most effective step in the whole process.
9. Lighting for approval
Color looks different under shop fluorescents, warm LEDs, and afternoon sun. Metallics shift the most. Approve color under a consistent standard illuminant, typically D65 (daylight), in a light booth or at least a consistent location. If your end customer views parts under a specific light, like an indoor retail display, check under that light too.
Look at panels side by side, at the same angle, at a normal viewing distance. Arm’s length is fine. Six inches is where every panel looks slightly wrong.
10. Keep it on file by part number
The spec only works if it is attached to the part. We keep your color and finish on file so run twelve looks like run one. That record includes the powder product code, lot history, gloss, texture, mil range, masking notes, and the approval date. You reorder by part number. Nobody has to remember anything, including us.
A minimal spec sheet looks like this:
| Field | Example |
|---|---|
| Part number | BRK-1142-R2 |
| Substrate | Steel, hot-rolled |
| Prep | Blast, iron phosphate |
| Powder | Manufacturer + product code |
| Color | RAL 7016, smooth |
| Gloss | 25–35 GU at 60° |
| DFT | 2.5–4.0 mils |
| Masking | M10 threads, ground lug face |
| Master | Panel dated at first-article approval |
This is what OEM production runs and architectural and furniture work need most, and it is a large part of why customers pick us. The same color, every time, on purpose.
If you have a part and a color and want them written down properly, send the part number, drawings or photos, the color target, and your volumes through the quote page. We will come back with a proposed spec along with the price.