色・発色
opal glass
Japanese: オパールガラス
Glass made opaque to translucent using a milking agent.
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Opal glass is a type of glass that contains opacifying agents such as fluoride, phosphate, and calcium compounds, causing light to scatter within the glass and giving it a milky white, translucent to opaque appearance. Unlike clear glass, it allows light to pass through while diffusing it, resulting in a soft, uniform light transmission. It is available in a wide range of colors, from white and cream to colored opal.
When combined with clear glass, opal glass allows for a wider range of expressions in terms of color contrast, layering, and a sense of diffusion. When fusing, it is essential to use opal glass with the same COE as the clear glass. Some opal glasses contain fluorine-based opacifiers; since their opacity may change at high temperatures or volatile components may be released into the kiln, care must be taken with kiln ventilation and firing temperature control.
Related Concepts
By comparing materials with opacifiers, fluorescent glass, and color sample tiles, and gaining an understanding of their optical properties, you can expand the range of color design possibilities for your artwork.
This entry is written in Japanese by Rei Chikaoka and translated for readers outside Japan. If something reads oddly, the original is the source of truth.