<?xml version="1.0" encoding="utf-8"?><metadata xmlns:dc="http://purl.org/dc/elements/1.1/"  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dcterms="http://purl.org/dc/terms/"><dc:title xml:lang="en">casein plastic</dc:title><dc:identifier>http://AATesaurus.cultura.gencat.cat/aat/getty_en?tema=31370945</dc:identifier><dc:language>en</dc:language><dc:publisher xml:lang="en">Getty Institute</dc:publisher><dcterms:created>2026-03-30 20:40:02</dcterms:created><dcterms:isPartOf xsi:type="dcterms:URI">http://AATesaurus.cultura.gencat.cat/aat/getty_en</dcterms:isPartOf><dcterms:isPartOf xml:lang="en">Tesaurus d&apos;Art i Arquitectura</dcterms:isPartOf><dc:format>text/html</dc:format> <dcterms:alternative xml:lang="en">Karolith</dcterms:alternative> <dcterms:alternative xml:lang="en">milkstone</dcterms:alternative> <dcterms:alternative xml:lang="en">plastics, casein</dcterms:alternative> <dcterms:alternative xml:lang="en">Lactoid</dcterms:alternative> <dcterms:alternative xml:lang="en">Aladdinite</dcterms:alternative> <dcterms:alternative xml:lang="en">casein plastics</dcterms:alternative> <dcterms:alternative xml:lang="en">plastic, casein</dcterms:alternative> <dc:description xml:lang="en"><![CDATA[ Thermoplastic molding materials prepared from casein, a natural phosphorous-containing protein found in milk. While trying to make a waterproof coating in 1897, Adolph Spitteler and associate W. Krische of Germany discovered that casein becomes hard and insoluble when treated with formaldehyde. Casein plastics were used for small items such as buttons, beads, buckles, combs, fountain pens, umbrella handles, cutlery handles, and knitting needles; they are often pigmented to simulate ivory, horn, or tortoise shell. ]]></dc:description></metadata>