The term for that is a bidirectional reflectance distribution function (BRDF). No idea about libraries of BRDFs for common materials but considering how even games have moved to physically-based rendering there must be.

https://en.wikipedia.org/wiki/Bidirectional_reflectance_dist...

The original PBR paper cites a materials database made by one of those big Japanese companies many years ago (I think it was Mitsubishi?)

EDIT: found it! It’s called MERL (https://merl.com/brdf)

Modern PBR specifically doesn’t really rely on artists choosing a BRDF though. The idea is to pick one that’s accurate, and expose a handful of variables to control it (roughness and metalness mostly)

I don’t know if one exists.

But if it does, I am not sure how useful it would be because the effort to get an ink/paint that met all those requirements would be at least as complex as the Pantone factory.

Probably more complex since Pantone designs colors for the production facilities they have in existence (or can procure).

Basically the problem is who will make the color you specified?

There are problems with Pantone, but availability is not ordinarily among them.

There is no "open source" because it is a shitton of work someone has to pay for it and actively manage, and open source means anyone else could just take your income source (selling the paint catalogs) and re-make it cheaper.

If you're buying a lot you can just design the color, get a bunch of samples mixed and pick one.

Hell, you could go to good paint shop and get anything you want matched and get a recipe for it, that's how car can be painted to match the paint that changed the color with age.

Just costly for anything not mass market.

A paint shop does not perform the testing required to confirm a paint meets the classes of specifications the GP of your comment describes.

Achieving that level of known properties requires equipment, personnel, and materials beyond what would make commercial sense outside of the market segment in which the cost of Pantone systems make sense.

To put it another way, cost of entry is Pantone’s moat and why it has been filling the same market segment for many decades…where $21/month is pretty much no different than free.

Also a paint shop does not do that for free. I remember going to one and while talking to the owner his subordinate kept walking up and asking if this is the right color (they were matching) and the owner said, I think it needs a bit more ... 5 minutes later he would come back and show him and keep iterating. I don't think you can always just put some paint sample under a light and have a computer spit out RGB. It takes time and IS expensive to match paint, especially automotive, etc..

It would be an appropriate undertaking for something like NIST, I would suspect.

An attempt was made: http://adaptstudio.ca/ocs/

In Europe everyone uses RAL, not Pantone, for selecting paint colours, though I'm not sure about exact differences between those colour systems.

RAL has some serious coverage gaps. Classic RAL has crummy oranges and pinks, for example (though they did recently fill a major gap with HN-orange-ish, it's not in my deck, so it may as well not exist!). Design D2 is much, much better, but still not really adequate in many areas that Pantone does cover.

But RAL is definitely the better choice for anything but printing... if it has your color (colour?).

Germany also has HKS [1], which is irrelevant on a global scale but fairly popular for domestic printed media.

[1]: https://en.wikipedia.org/wiki/HKS_(colour_system)