Contemporary methods of making stained-glass windows differs only in details from those employed in medieval times.
At the beginning there is made after sketches and small scale projects so called carton in life size. Then the lines which define divisions between pieces of glass should be copied from the carton to tracing paper. The next steps are: transferring these lines by the means of carbon paper to a Bristol board and simultaneous numbering of copied parts which will later enable their identification. After cutting the Bristol board up these parts will serve as templates for glass elements.
The next and very important stage is determination of general coloring and deciding what color glass should be used for every particular piece of glass.
The glass used for stained-glass is tinted in glass works and - like it was done in past - is made manually according to special recipes which allows to achieve a proper texture and transparency. The pieces of color glass cut after templates are being fastened to glass tile with melted wax, each in its place. This enables to put part of stained-glass on painter's easel and to back light it. The painting is done with dark paint containing glaze and metal oxides. Depending on the thickness of paint it is possible to achieve light stumble or complete opacity. To paint the stained-glass means to cover with paint some parts of glass and modifying or cutting off this way the light coming through the stained-glass window. Usually the process of painting is repeated few times, the glass is baked after each painting. The temperature of baking is 650oC to obtain durable fusion of paint and glass. After that individual parts are being fastened with lead T-bar soldered with tin.
The alternative methods with specific expression of their own are: technique invented by Louis C. Tiffany (edges of pieces of glass are wrapped in copper foil and then soldered with tin) and technique called dale de verre (pieces of thick glass are kept together by the means of concrete or epoxy resin).