Nicholas Savard

Large Black And White Glass Overlay Bowl Attributed Moser Carlsbad

A wheel etched overlay glass vase attributed to Moser from the Czech Republic

About "Overlay Glass"

The molten glass must be mixed with metal oxides for this purpose. Red glass is colored with gold, amber glass with silver, blue with cobalt, green with iron and chrome. The color is therefore already present in the molten glass and is not painted or sprayed on later. That is why it does not wash off. This is then called genuine “overlay glass”.

Now it gets complicated: To achieve the two-tone effect, another layer of colored glass must be fused on top of a crystal-clear layer of glass. This is a very difficult task for the glassmakers. First, a crystal clear “Kölbel” is made, which is a small glass bubble. This glass bubble is then dipped into the colored melt, the two layers fuse together but do not mix. This cannot be done by one glassmaker alone, it takes a whole team of at least five glassmakers and helpers.