You can use a special glue to chip the surface of glass, creating feathery patterns that resemble frost on a window in winter. This can be applied to any colour of glass, but the surface of the glass needs to be etched first, to allow the glue a surface on which it can stick properly. Glue-chipping glass stresses the surface of the glass, so very thin glass is more likely to break. This process is best accomplished when the weather is dry and sunny, as humidity keeps the glue from drying properly.
Wash the glass very thoroughly to remove all the dust or other material left from the etching process.
Apply tape around all edges of the glass so that it is attached smoothly along the flat side of the glass that will not be glue-chipped, then folded up over the edge so it overlaps the side of the glass where the glue will be applied. This creates a rim so the glue cannot drip over the edge.
Place old newspaper over the work surface to catch any spills.
Set the glass on the surface and use the level and shims to make sure it sits as level as possible to prevent the glue from pooling too thickly in one area and too thinly in another area.
Mix the glue with cold water in a container that fits in the double boiler and holds enough glue to cover the entire surface of the glass in a layer 1/16th to 1/8th inch thick. The generally recommended recipe is glue to water in a ratio of 2 to 1. Steve Fregeau of the Glass Mart recommends mixing 44.4ml of glue with 85.1gr of water for one square foot of glass.
Mix the dry glue and water, and allow it to sit for an hour while the glue absorbs the water.
Heat the mixture in the double boiler very slowly until it is between 60 and 65.6 degrees Celsius. Monitor the temperature with the candy thermometer.
Pour the warmed glue mixture onto the glass. You can use the turkey baster for a more controlled application.
Allow the glue to cure for up to two hours, depending on the temperature and humidity of the work area. This may require more time if it is very humid in the area, although it is not recommended to try this when it is very humid out.
Remove the tape, and allow the glue to finish drying, which can take up to 24 hours.
Use a source of indirect heat to start the chipping process of the glue. This can be a small space heater, a fan to circulate warm air or direct sunlight. Use extra care when moving the glass, however, because the surface is under a lot of stress at this point.
Wear safety glasses once the glue starts chipping off because it can pop off with some force.
Clean up all the small chips of glue and glass left after the chipping process is finished with a dustpan and brush or vacuum cleaner.
Clean the glass. This may require application of warm water to the glass to remove any glue that did not chip off. Particularly stubborn patches of glue can be removed by leaving a soaking wet rag on them for a number of minutes until the glue can be wiped off.
Do not allow pets access to the work area. The glue is made from animal gelatin, which pets like to eat, but the glue that chips off the glass has glass shards in it that could kill your pet.