Rault of Rennes, France
The Raults achieved the true colour of gold by using genuine gold dust in a colloidal suspension. The 2-centimetre thick chunks of dalle de verre were trimmed by striking the edges with jewelers hammers.
The use of conventional lead cames (channels) for heavy dalle de verre seems to be unique to the Raults. Most studios used various cement mixtures to support the extra weight; but this smothers the gorgeous light refraction of the exposed edges.