he ancient leaded-glassworking art consists in using interspaced strips of lead to support the sheets of glass. First of all a drawing is made on cardboard from which a traced copy is produced which is then cut into as many pieces are those making up the chosen motif.
After placing the cardboard shapes over the glass, this is then cut using diamond. When cutting, account must be taken of the thickness of the drawn lead and then the shapes are reduced in size by a few millimetres. After cutting the coloured glass, the pieces are put together over the basic design and, starting in one corner, the H-shaped lead profile of a glass is fitted, then another and another and so on until the composition is finished. All the lead joints are adapted and then sealed with tin on both sides.

The glass is then painted using earth oxides mixed with oil of turpentine and other types of resins. All this is then placed in an oven at a temperature that causes the glass to melt and absorb the colours, making these indelible.

Another production technique is melted glass. This consists in placing several layers of glass of different colour, one on top of the other and then bringing these to melting temperature, thereby producing special colour effects.