Lead drawing involves transposing an artist’s work by selecting the most suitable glass-cutting (therefore the position of the lead) according to the treatment and colour. This work is carried out by enlarging the original design to the size of the window itself. The subtle interpretation of the artist work by our stained glassmakers requires all-round artistic ability, perfect understanding of the original piece and excellent technical expertise to create a piece that is as close as possible to the artist’s intentions.
Like sewing, glass-cutting uses a full-scale pattern cut using triple blade scissors due to the thickness of the lead. The pieces that make up each piece are chosen to suit the subtleties in each part of the glass plates and then hand cut.
The glass plates can be coloured in bulk and made up of one or more layers of colour applied on a sheet of white glass when firing. Engraving the glass plate using hydrofluoric acid involves either lightening the colours by diluting them or erasing them to show the underlying colour/s. This process creates a wider variety of tones in the same colour or a multicolour pattern in the same piece of glass by avoiding having to put several pieces together and using lead came. Sandblasting is the process of projecting fine sand at high pressure in precise areas defined by a stencil to strip the upper layers of the glass and thus inscribe patterns of high precision in the material.
Made from enamels or metal oxides, the paint and grisaille are applied to the glass before firing. They can enhance the shaded parts of a pattern or drawing, or to bring subtle nuances to the original color of the glass.
Lead is used to assemble the glass pieces to create the window. It is H-shaped to fit two pieces of adjoining glass. It is available in different thicknesses and can also be fitted with a flexible metallic rod to make it more resistant to bending and marking whilst keeping its flexibility. Lead is welded using tin.
The Atelier not only sees the window from its design to its installation but is also present at any height required to install the stained glass window in the building. The same craftsmen who work on the original design to choose the leadwork, choose the colours, cut the glass, paint the grisaille, engrave using sanded acid, fire the glass and assemble the window are the same people you see perched dozens of metres high on top of scaffolding to fit the fruit of their work. The same craftsmen dismantle windows, restore them and replace them once they have been restored in the workshop.