Optical Illusions in Glass

When purchasing supplies for my crafts, I try to support my local stores. However, that is not always possible. When I first started fusing, one of the on-line sites I purchased from was Delphi Glass in Lansing, MI. This company has numerous free patterns and project ideas on their website.

One of the projects that I tried a few years ago is the “Woven Stripes” square plate (Delphi Project Guide found here). To make the plate, I purchased some Vienna Stripe glass. The glass is a semi opaque white with lines of color on the surface.

This project was made with a clear base layer and squares of the striped glass placed in an alternating “woven” pattern. Over every other striped square (those going in only one direction) a square of clear glass was placed.

Fusing glass is normally sold in sheets that are 3mm thick. Thus, the design involved some areas with two layers of glass (making these areas 6 mm thick), and some areas of three layers of glass (9mm thick).

However, glass has a natural tendency to want to be 6mm thick. When fired at a full fuse temperature, the areas of clear glass spread outward to create the 6 mm thickness. This project created a bit of an optical illusion. In the areas where the clear glass spread, the lines appear slightly curved.

Recently, I tried another variation of this optical illusion. I though that if one piece of glass caused the stripes to curve, then maybe two pieces of glass would create a greater curve effect. Because I was stacking more glass, I opted not to use a clear base layer, to avoid the project spreading out too much. Rather, I used the my excess Vienna Stripe glass as a single base layer. To accentuate the extent of curve, I kept the strip going only one direction. Over the striped glass, I stacked two pieces of clear glass in an alternating fashion, leaving an uncovered area of the base glass between each double stack of clear glass.

The optical illusion I was hoping for worked our really well. Unfortunately, the base layer was not a solid piece of Vienna Stripe, but rather four pieces placed side by side. At the full fuse temperature, the glass naturally tried to settle to 6mm in thickness. This caused contraction in the areas of a single layer of glass and a couple of holes to open up.

I will admit that I was a bit disappointed with these holes because I had originally planned to slump the project into a square plate mold. I pondered some ideas for how to cover the holes, but was not really happy with any of my ideas. When I showed the project to my husband, he suggested that I run some ribbon through the holes as a way to make the project a piece of wall art. I like that idea. And, since the top holes were very symmetrical, it worked well. For the hole at the bottom of the project, I cut some flower petals out of the last bits of Vienna Strip, contour fused them together and hung the flower from the bottom. I think this would make a lovely piece of wall art. If anyone is interested in the piece, please contact me and I will make arrangements for it to be sent to you.

I really like how this optical illusion project turned out and decided to try another idea – a round approach to the same illusion. Unfortunately, Vienna glass is no longer sold, so I needed a different source for my stripes. To do this, I placed stringer pieces around the perimeter of a circle of clear glass in an alternating pattern of two color sets each with eight sections. Two pieces of clear glass was stacked over one set of colors around the perimeter. And, two pieces were stacked over the other color sections but at a position more towards the center of the circle.

I really like how this project turned out! It resulted in an octagon shape that I then slumped into a shallow plate form.

I have some more optical illusion ideas that I will be trying in the future.

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