Flashed glass
Flashed glass , also called cameo glass , is flat or hollow glass that consists of two or more layers of different colors.
When flat glass is frosted glass best known, which is used for example for glare-free illumination or translucent window in sanitary rooms.
history
Vessels were made from cameo glass as early as ancient times. The production was possibly similar to the terra sigillata vessels with negative forms of the reliefs. The white, thickened glass powder was brushed into it, then the glassblower blew the colored glass mass into the shell mold. This was removed after cooling. The heat had melted the glass powder onto the colored glass and depicted the shapes of the reliefs. A grainy structure of the white glass mass can be traced back to this manufacturing method.
Overlap glass was used for hollow glasses especially in Hellenism , Biedermeier , Art Nouveau and East Asian glass art. At the end of the 19th century, Emile Gallé continued to develop glass art, created Art Nouveau designs and employed a large manufacture in Nancy.
Manufacturing
There are various manufacturing techniques for flashed glass today:
- Flat glass is produced by fusing glass ribbons made of colorless clear glass and cloudy glass , which are drawn simultaneously from neighboring melting tanks
- Hollow glass is made by simply dipping the slightly inflated glass hanging from the glassmaker's pipe in front of it from colorless glass into colored glass and then blowing it up. Or, conversely, a small amount of colored glass is dipped into colorless glass, in which case the amount of colored glass to be used is better under control. This is how the lead crystal wine glasses, often referred to as Romans , are made . By later grinding out or etching of patterns, interesting effects are achieved through the colored contrast.
- You can also melt the colored glass in the form of rods onto the colorless glass and spread it evenly over it using an iron.
A process for the production of flashed glass goes back to Ernst Jähde , founder of the glass factory "Johannahütte" in Schönborn (Niederlausitz) in 1899. The invention was registered for a patent on February 19, 1912 under the designation “Process for the production of glass objects with overlays or other glass supports” under the number 60369 in Austria. After this invention, flashed glass was produced for decades in the Schönborn glass factory.
- Examples
Roman wine bowl
Portland vase , dating disputed
Islamic cup, Iran, 9. – 10. Century
Overlay vase, approx. 1920s
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Web links
- Material archive : flashed glass , at materialarchiv.ch, accessed on February 3, 2016
Individual evidence
- ↑ Sarah Scheffler: Of erotic scenes and hot discussions. In: Archaeological Calendar 2015, Zabern Verlag