The technology of drawing on glass yellow glaze known since the 11th century.But it The Bedrich Egermann, 30 years of the 19th century, have invented a frosting red and it made him famous throughout Europe and overseas. Glaze (in the Czech Republic is called glaze) is a very complex physico-chemical process during which, at high temperature, the surface of the glass includes particles of silver,gold or copper and stained glass in ruby color. The coating has a thin layer, but very strong and most importantly healthy. The product was then processed by the grinder and engraver. No replicas and fakes,
The safety is very good, but there are small scratches on glasure, which is not surprising given the age of the subject.