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Striking is a process in which the color or transparency of a particular glass changes after being fired in the kiln.  In some cases this is desirable, but in many cases the effect is not wanted. Red glass (especially glasses with cadmium red) tends to strike more often than other glasses.  

Striking is related to the manufacturing process and to how the colorants in the glass precipitate in the glass as it cools.  The process goes something like this:

1. The manufacturer rolls out the glass into sheets.

2. The sheets cool, with the coloring substance precipitating in the glass as it cools. This gives the glass its original color.

3. Because the sheets of rolled glass cool very fast, some of the coloring material is trapped in the glass -- it doesn't precipitate as a visible color, it's just there.

4. Later, when you reheat the glass in your kiln, there is a temperature at which the color will precipitate again, changing the color (and the color density) in the glass. This range appears to differ for different glasses, but is somewhere from around 1150F/620C to fusing temperature.

Click here for more about striking.


Copyright 2005 Brad Walker.  All rights reserved.

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Copyright 2005-2006 by M. Bradley Walker.  All rights reserved.

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