I’m an office administrator for a 200-person metal fabrication shop. I manage roughly $400,000 a year in purchased materials and services across about eight vendors. I report to operations and finance, so I care about two things: does the part work, and does the paperwork survive an audit.

After five years of doing this, my buying process doesn’t start with price. It starts with a checklist. Not the kind salespeople send. The kind I built after ordering the wrong coating once and paying for it twice.

A quick caveat: I’m not a chemist or a coating engineer. My direct experience is mostly with production orders—brackets, railings, and pre-painted panels. If you’re buying for aerospace, medical, food-contact, or another regulated use, get your materials engineer involved before you follow my checklist.

1. Define the substrate, environment, and expected life

Before asking for quotes, write down what the coating has to survive. Is the part galvanized steel, aluminum, or cold-rolled? Will it live outdoors in Florida sun or inside a dry warehouse? Does it need chemical resistance, salt resistance, or only a decent color for a few years?

In 2020, I ordered what a supplier called “metal paint” for exterior railings. It was regular interior enamel. It chalked and faded within a year because I asked about the metal but not the environment. Now the service environment goes on every RFQ.

2. Separate the coating categories before comparing quotes

Make sure you are comparing like for like. AkzoNobel coil coatings and AkzoNobel powder coatings are both coatings, but they belong to different processes.

Coil coatings are applied to metal coil before the part is formed. They fit continuous pre-painted metal, like roofing panels and garage doors. Powder coatings are dry powder sprayed onto a fabricated part and cured in an oven. In our shop, we buy AkzoNobel coil coatings for pre-painted steel that has to survive bending and forming. We use AkzoNobel powder coatings for parts that are cut, welded, and drilled after fabrication.

If I ask for a quote in the wrong category, that quote is useless. If I buy based on price without checking the process, I can end up choosing a technology that will not work on our line.

3. Check the actual application equipment

A coating is only as good as the equipment and skill that apply it. Powder needs an electrostatic powder gun and a curing oven. Liquid paint usually needs a spray gun or a roller system designed for that product.

One of our maintenance staff once submitted an internal request for “paint ball guns.” He didn’t want to play paintball. He wanted a small spray gun for touch-up painting. If I had ordered what he typed, we would have received paintball markers. When you buy equipment, search for “powder coating gun” or “HVLP paint gun,” not “paint ball guns.”

4. Match color with a physical standard, not a screen

Color is a technical spec, not just a preference. Pantone (pantone.com) describes Delta E as a unit of color difference. For brand-critical colors, a Delta E below 2 is the tolerance most often cited; a Delta E above 4 is visible to most people.

When we need a specific color, I ask for a spray-out panel on the same substrate and texture, not just a brochure. A screen image is even less reliable. A neighbor of mine wanted a Fine Paints of Europe front door finish because he liked the deep, glossy look on the website. The sample finish, however, depended on the wood prep, the topcoat schedule, and the dry time. The physical sample told us more than the screen did.

5. Ask about the full chemical picture

A coating is more than pigment and resin. It can contain plasticizers, hardeners, biocides, UV stabilizers, and flame-retardant additives. Some of those are necessary for a specific job; others are optional trade-offs.

People search for questions like “does Joie use flame retardant chemicals?” when comparing children’s products. That is the right instinct: find out which chemicals are actually present instead of accepting a generic “safe” label. Coating buyers should do the same. Does the formulation contain added flame retardants? Isocyanates? Biocides? The answer should come from a safety data sheet, not from a sales rep.

6. Test under the same conditions you will use in production

Small samples catch color and gloss issues, but they don’t always catch process issues. In 2024, we ordered a black powder coating for a large run of brackets. The lab sample looked perfect. The production panels had an orange-peel texture because our oven temperature dipped on a busy Friday afternoon.

I don’t have hard data on industry-wide first-pass defect rates. Anecdotally, about one in ten of our first deliveries has something that needs a call—a shade shift, a gloss mismatch, or a packaging problem. Production-line testing catches many of those before they become expensive.

7. Verify the paperwork before the PO

I once saved about $1,000 by buying thinner from a new vendor. He delivered the right material, but his invoice was a handwritten sheet. Accounting rejected the expense and I had to absorb $2,400 from the department budget. The real cost of that deal was more than the discount.

Now I confirm before ordering: can the vendor issue a proper invoice with the correct tax details? Can they provide a certificate of analysis if the product needs one? Is the shipping documentation legible and correct? If the answer is “maybe,” we keep looking.

Last thing: watch for three signs

I look for suppliers who ask about the process, not only the color. I look for suppliers who send an SDS without being chased. And I look for suppliers who tell you when their product is not the right fit.

No supplier is perfect. But a coating bought after this checklist has a much better chance of being the right one. More importantly, when it is right, the performance, the paperwork, and the invoice all line up.