@futurebird we wind up with Red Yellow and Blue as “primaries” as a quirk of how cheaply available paint pigments *happen* to mix as a result of their particular pigment properties- combined with a need to simplify concepts for children… particle size, spectral reflectance distribution, spectral absorption in which pigments act as filters for lower layers of paint…

simulating this is a project i have spent years and years on

@futurebird we wind up with Red Yellow and Blue as “primaries” as a quirk of how cheaply available paint pigments *happen* to mix as a result of their particular pigment properties- combined with a need to simplify concepts for children… particle size, spectral reflectance distribution, spectral absorption in which pigments act as filters for lower layers of paint…

simulating this is a project i have spent years and years on

@bri_seven @futurebird I remember some software manufacturer advertising a more "realistic" way of mixing colours in their paint program, some years ago. Do you know, or have you been involved?

@slowtiger @futurebird Corel’s Painter (formerly metacreation’s painter) had a paint simulator in it, that actually ran a bit of a particle physics simulation for a second or two on each stroke. I wasn’t involved and i haven’t made any work public

@slowtiger @futurebird l sorta glossed over it but, the most nasic thing to understand about paint is it is particles of “pigment” , little chunks of rock and oxidised metal too small to see; suspended in a medium, and layered over the top of each other.

each kind of chemical has a spectral fingerprint that makes a color when it absorbs and reflects light- and usually the inverted color when it is heated- which is how we are able to know the chemical compositions of distant astral bodies.

when they’re in paint the pigment partkcles kinda sit next to each other and on top of each other; and produce a color by light kinda penetrating into the paint layers a bit, bouncing around getting absorbed, coming out as a different color

@slowtiger @futurebird and so when two pigments mix, it’s a simplification, but you can mathematically model an approximation of the mixing by particles having surface coverage, and taking the average color across the surface

so the reason alizarin crimson is “strong” for example is its particles are much smaller than other pigments by an order or two of magnitude, and fill in all the gaps like sand between paving stones… on top of the paving stones, all over. that.. gets a little tricky to model accurately