In fusing glass there are many techniques and variations within each technique. One technique that is frequently incorporated in Susan's work is the use of inclusions. An inclusion can be any object fused between two pieces of glass. Metals such as copper, aluminum and brass are often used as inclusions. These metals can be used in the form of foil, mesh, wire and metal leaf. When fusing objects between two sheets of glass it is important to pay attention to the thickness of the item. If it is too thick it could cause the glass to break or cause large bubbles. To reduce the production of bubbles use metal that is thin as possible to create the desired effect and use a bubble reduction schedule when firing.
During the process of firing, copper oxidizes. The areas that oxidize the most turn turquoise, the areas with less oxidation turn red. The oxidation occurs in the kiln in the hours before the glass begins to fuse. Once the edges of the glass have fused, the oxidation process stops.
In the picture on the right, a sun pattern was cut out of copper foil. Black glass was used for the bottom layer, the copper foil was placed in the middle and clear glass on top. In this example, Susan applied glaze over the sun pattern and portions of the surrounding area to protect the copper from oxidation. After firing, you can see the unprotected area of the copper has changed to bluish black at the outside edges fading to red.
There are certain metals that will have a reaction with the metals in the glass. When a reaction happens either the metal will shift in color as seen when silver foil reacts by turning a yellowish gold or the glass touching the edges of copper will have a brown outline with certain colors of glass.
The piece on the left started with a layer of Dichroic glass. Silver leaves were cut and placed in the middle and a clear piece of class was placed on top.
In the example on the right, copper wire was cut, bent to form a design the artist created and then hammered flat. Dichroic glass was used on the bottom layer, the copper design was placed in the middle and clear glass was used on the top. Copper will turn red unless a glaze is used over it. In this case, the artist wanted the effect of oxidation to change the color of the copper.
Although metals are the typical choice for inclusions, many items can be used. Organic materials such as leaves and feathers will often times leave an impression once the object burns away. Shells do not usually do well but you may experience better success fusing very small sand dollars with a very slow schedule to reduce bubbles. Other objects that can be used include enamels, mica and fiber paper. The possibilities are all around you.
Inclusions don't have to be a material, air bubbles can be used as a nice design element. The large piece on the left is made of reed glass. Reed glass has very small ridges that run across it. Two pieces were set at 90 degrees to each other and fired. Where the ridges crossed, tiny air bubbles formed creating this pattern.
In the second example, two pieces of clear glass were used. A thin paste of water and baking soda was spread on the glass and allowed to dry. During the firing process, the baking soda formed air bubbles of different sizes.