How the light
was split.

01 The concept

PRISM is a dark room with one white beam and no colour in it. The brand is the demonstration itself — Newton's experimentum crucis handed to you: your cursor is a glass prism, and colour only exists where you hold it in the light.

It belongs to Wave IV, "Second Person" — the page is inert until the visitor drives it. Nothing here animates on its own. The beam is a straight white line until your hand intercepts it; move away and the spectrum folds back into white and the room goes silent. The single job of the page: make you feel that you are the one who split the light.

02 Palette

Argued entirely from a beam in a dark room: near-black for the room, a warm off-white for the light, brass for the instrument, and the full physical spectrum reserved for the one thing the visitor makes — the fan. Per the collection's ink/line rule, brass is used for rules and marks; body copy stays warm-white for contrast on the dark.

03 Type

Spectral (Production Type) carries the voice — a serif with sharp, optical terminals that suit a page about light and glass; set light (300) at display size for the headlines, italic for the word the whole page turns on ("light", "split"). Space Grotesk handles every instrument surface: the eyebrows, the live readout, the wavelength column, the cues. The pairing is deliberate — a humanist optical serif for the poetry, a precise grotesque for the measurements, so the reading voice and the instrument voice never blur.

04 Techniques

• Two WebGL layers — a full-viewport scene canvas behind the copy renders the room, the beam and the fan as emissive light; a second tint canvas above the copy, in mix-blend-mode: multiply, carries only the fan's colour so it paints over the white words wherever the spectrum falls.
• Real refraction — every frame, Snell's law is solved for 24 wavelengths through a 40° glass prism, with a Cauchy index (n ≈ 1.72, rising toward violet). The angle at which you hold the prism sets the angle of incidence, so the fan genuinely tilts and widens as you move — the geometry is derived, not drawn.
• Dispersion — each wavelength leaves the glass at its own deviation; the physical spread is small, so it is magnified for the screen while keeping the real relative ordering (red bends least, violet most).
• Fraunhofer lines — the fan carries faint dark absorption lines at the true solar wavelengths (Hα 656, Na-D 589, Hβ 486, G 431 nm). Hold the prism still and they sharpen.
• The prism cursor is an inline SVG glass triangle in a brass mount, tilting with your velocity — engraved, if you look, "N°96".

The signature is the whole page: a physically-fanned spectrum that exists only where you hold the glass. The scene layer makes it light; the multiply layer makes it ink — so the same fan you sweep across the dark wall also tints the sentence it crosses, then lets it go white again the instant you move on.

05 Iteration log