Light Box

The glass needs to be lit from behind during the painting process to simulate what it will look like when installed as a window. To paint large panels, Leap attaches the individual pieces of glass to a larger piece of plate glass, a process called "waxing up." The glass can then be painted by placing it on a glass easel in front of a light source.

The Centaur was made by painting black pigment over colored pieces of glass. This is the most basic technique of glass painting and it is identical to the way church windows were made as early as the 12th century. The faces on the light box expand on this technique. Black pigment was painted onto clear glass and fired. Afterwards, colored pigments were applied and then fired again. The application of colored pigments is called enameling. It came into use during the 15th century. Leap's animals are frequently painted like the sleeping chipmunk, lower left. They are completely rendered in black pigment before color is applied.

Flashed Glass

Most of the glass Leap uses for his windows is mouth-blown and colored all the way through. For detailed areas, he frequently uses "flashed" or "overlay" glass. This type is characterized by having a thin layer of colored glass only on one surface. The color can be removed by sandblasting or acid etching.

Glass Paint

The pigments used for painting on glass are made from glass frit and metal oxides. They are sold in powder form and can be mixed with different media to achieve different effects. Leap mixes black pigment with an oil, and paints with a long tapered brush called a tracing brush to create the line work in his pieces. Tonalities are created by mixing the same pigment with water and applying it with a badger hair blender brush or an airbrush.


This mannequin holds a fine pointed tracing brush made from fitch hair, and a badger hair blender brush. The blender is used to remove brush strokes when laying down a broad application of paint called a matt. The tonal details in glass painting are achieved by skillfully removing pigment from the dark field of the matt. A variety of stiff brushes and quills are used for this purpose.


The pattern for a stained glass window is called a cartoon. It contains the drawing of the details that will be painted onto the glass as well as the outline of the individual pieces of glass that make up the panel. Colored pieces of glass are cut to shape with a glass cutter using the pattern as a guide.


The image in this paperweight was painted with high temperature glass pigments on a small glass sphere. The sphere was then cased with more glass by dipping it into the furnace at the glass factory.

Stippling Brushes

After a layer of pigment is applied to the glass creating a matt, it is allowed to dry. A variety of stiff brushes and quills are then used to scratch away pigment from the matt to create details on the glass. The pigment can be manipulated in this manner because it does not become permanent until it is fired in the kiln.

Lead Came

After the glass is painted and fired, it is assembled using strips of lead called cames. Lead cames have a groove on each side into which the glass fits. Solder is used to join the leads where they intersect.
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