I am wanting to produce some paint color samples that are kept at the facility in storage (protected, in a file cabinet) that will be considered the authoritative standard by which all paint color accuracy is judged, whether it's something we order tinted by a vendor, or something we self-tint.

It sounds like it should be as simple as getting the colors we wanted tinted in a finish that has the least chance of yellowing/drifting over time, but I am not really sure what's available out there that basically doesn't drift much.

Every conversion varnish I've ever sprayed (MLC, SW, Chemcraft, Axalta, Becker) has a slight drift toward yellow over the course of several years. It's very subtle, but noticeable especially on grays and bright whites.

We have about 15 colors we'd like to do this with, and consider our "stock" colors.

Any suggestions on what I need to be looking at? Or, does anyone know of companies that will produce solid color samples like this from a material that resists drifting over time, for a reasonable price (ie, not thousands of dollars for a few sample colors)?

My understanding is that Acrylic 2k urethanes are about as light stable as it gets, a bit pricy but if color stability is your goal, i think that's the way to go.

Can't knock urethane acrylics, great stuff, but even with it inhibiters, urethane will age over time.. On top of that, light fast colors are the only ones that will not change with age and these would be the standard colors that have been used for well over a century in finishing...Earth colors, burnt umber, burnt sienna, raw umber, raw sienna, Black...(preferably Carbon), yellow ochre, ultra marine blue and green, and other reds, blues and greens that are proven stable colors in the industry..!! Those, ground into a CAB Acrylic, will be stable for well over your life time, mine were still stable after 40+ years, before retireing..!!

Ok, I hadn't thought about the pigments themselves changing but that makes sense. I have no idea what my local Sherwin Williams is using to tint CAB lacquer.

We only buy CAB lacquer on the occasion we need to do touchup in the field in large amounts, but this might be our go-to for this purpose.

How long, I wonder, will CAB lacquer stay stable in a tightly sealed can?

I have a partial can of Delta Cab lacquer, that is more than 30 years old that is still crystal clear, if that helps your decesion at all.

PS: as to colors used by SW, I can only speak to as to what was being used in the 90's which were HULS, Pigments 844& 896, which were supposed to be permanent...but only time will tell if that's the case or not..!! Call them and ask if these are as stable as earth colors I listed or not.!!

Thank you for that Chemmy!