Optical Illusions with Glass Frit and Glass Displacement

Recently, I have been “playing” in my glass studio each morning trying out some new ideas. By doing this in the mornings, it allows me to set up something in the kiln to fire during the day. The next morning, I get to see the results of my previous day’s efforts. It gives me something nice to see (as well as a few surprises) when I open the kiln.

Lately, I’ve been playing around with how the placement of the glass can create optical changes after being fired.

Stenciling with Frit Glass.

For this project, I placed a couple 6″ stencils on kiln shelf paper and sifted some fine glass frit over the stencils. I then carefully removed the stencil and fired the glass using a Tack Fuse Schedule (max temp 1325 degrees, no hold time). This schedule resulted in the glass lightly fusing together without dramatically changing the size. I selected fine frit for two reasons (1) I have lots of it that I don’t use in other projects and thought this would be a good way to use it, and (2) I wanted the image to be more abstract and thought that powdered frit would be too exact for what I wanted to accomplish. This two thin wafers of frit were aligned, sandwiched between a piece of opaque white and a piece of clear glass, full fused and slumped into a shallow dish mold. The result was lovely. By placing the transparent orange wafer on top of the opaque red glass wafer, I achieved a color gradient that would have been difficult to achieve. I really like the look of the bubbles that were trapped around the frit as it melted into the sheets of glass.

Glass Displacement.

For this project, I wanted to see what would happen if I stacked various sized squares of opaque and transparent glass and full fused. Since glass naturally wants to achieve a 6mm thickness (1/4inch), the glass in the stacks should cause the lower glass to shift outward as the top glass settles down to the natural height. I used a 6″ piece of opaque white glass as the base. On top of this, I placed stacks with 3/4″ transparent (in various colors), 5/8″ opaque white and 3/8″ transparent. The area of the three pieces of glass in each stack was 0.56″, 0.39″ and 0.14″, which added up to 1.09″. By placing the stacks in a six by six grid, the glass should settle evenly on the base glass. However, to keep the edges straight, I did use a 6″ stainless steel form. After full fusing (max temp 1475 degrees, 30 minute hold), the edges were smoothed on my flat grinder and the glass was slumped into a shallow dish mold. The result gives the illusion of depth to the piece.

Frit Displacement.

For this project, I wanted to see if glass displacement would be visible using frit sifted over stacked glass. The thinking behind this idea was that the glass powder would settle onto the horizontal surfaces, but would not stick to the vertical surfaces. Then, as the glass melted and spread, the untreated vertical glass would displace some of the adjacent horizontal glass. My initial test of this idea worked well (sorry, I forgot to take pictures). I applied the idea to make another small dish. For the base layers, I used a 6″ piece of clear glass was placed on to of a 6″ piece of red frit and stringer glass. On top of this, clear glass pieces, 0.75″ were placed in a 5 x 5 grid. Over this, I sifted transparent blue powder. And, to add some variety, I placed a couple 0.375″ red transparent square.

Another Frit Displacement.

Could this technique be used to create slight shadowing around cut pieces of glass? To test out this idea, I created a design that matched a quilt block I had recently made. Powdered glass in a bronze color was sifted over this design and accent glass added. For the bottom of the base layer, I also created a design using glass with different white textures. This turned out lovely, but I think the frit displacement technique works best when the color of frit is more intense.

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