Black, taken apart.
One line of black ink, one strip of paper, a little water. Everything the black was hiding comes out, in order of patience.
The band
javascript·chroma.js
// the front eases in, then glides, slowing as the paper fills
const front = solvent + travel * (1 - (1 - t) ** 2.4);
const run = max(0, front - origin);
// each pigment rides a fixed fraction of the run, spreading as it goes
for (const { rf, spread, mass } of pigments) {
const centre = origin + rf * run;
const sigma = 1.6 + spread * sqrt(run) * 0.85;
const c = (mass * 9 / sigma) * exp(-0.5 * ((u - centre) / sigma) ** 2);
pixel = mix(pixel, pigment, c); // translucent layers on clear paper
}
References
