A blue-opal glaze where the color isn't from a colorant but from light scattered by tiny droplets of a separated phase suspended in the glass — physics, not pigment. Song-dynasty Jun-yao kilns (Henan, China, 11th-13th century) defined the look. Reads as moonlit sky, occasionally with copper-red flushes (Jun + copper trace = peacock or sang-de-boeuf bloom).
High-silica feldspar glaze fired to cone 9–11 in light reduction. Blue color is structural, not pigmented — phosphorus-rich glaze chemistry causes liquid-liquid phase separation on cool-down: nano-scale silicate-rich droplets (~50–250 nm) suspended in the glass scatter short-wavelength light (Mie / Tyndall scattering) and pass long-wavelength light, giving the opalescent blue. Add 0.5–2% copper oxide for the Jun-with-flush variant; reduction reduces Cu²⁺ → Cu⁰ giving sang-de-boeuf red blooms. Modern American Jun glazes (Pete Pinnell, Phil Rogers recipes) use phosphate flux additions to drive the phase separation. Hard to control reproducibly — the blue depth is a function of cooling rate.
character — structural opalescent blue, moonlit-glass register, occasionally copper-red bloomed.
Robin Hopper The Ceramic Spectrum (Krause, 2nd ed.); Daniel Rhodes Clay and Glazes for the Potter.
House vocabulary — terms ForMatter uses with intent.
Materials and processes for people who design and make things.
A local-first library of materials, processes, applications, and finishes — equal weight, citable everywhere, so a student can move from "what is this" toward "what's actually buildable here, now, by me." Part of the renato.design ecosystem — sibling of Plenum, Specimen, Ingenue, gesture, graf, and the Renato Rhino plug-ins. Form and matter, inseparable.
Half of teaching materials is teaching how the material is made into the thing. The standard subscription library was always light on that half. The wedge here isn't better samples or a prettier interface — it's treating Process as a peer entity, not a footnote.
Conway, Lefteri, Forty, Sparke, ASM, GIA. Every voice: Voices.
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