More circles: this 24" glass ceiling lamp shade was cut out, fused, kiln formed (2nd firing), drilled for wire cables, and hung in '07 for the crime of being functional art. Special opalescent glasses were stacked with pieces of float plate (window) glass and opalescent stringer (very thin glass rod). The opal glasses and stringer are special because they have the same Coefficient of Expansion (COE) as plate glass.
COE is a measure of how much a glass shrinks as it cools to room temp. Glasses that have a difference of more than 2 or 3 COE are not compatible. Most art glasses have COEs of 90 or higher while most commercial glass such as bottle or window glass have COEs well below 90. They will still fuse together when fired, but shatter when they cool or break days/weeks/years later depending on the amount of stress trapped inside- just like people.
The layup for the 1st firing was a bottom layer of 28" diameter by 1/8" thick, clear plate glass and then a same size layer of compatible warm grey opal followed by several layers of plate glass strips and arcs cut from 1/8" thick sheet using an ordinary glass cutter. Different colors of opal stringer were added last.
Fusing was done to maintain a relief surface as was the later kiln forming when the glass was re-fired to slump over a bowl shaped, stainless steel form.
There was no design drawn up to start with. Rather glass was cut, laid out, changed, recut, and changed again- watching for how the shapes interacted and, based on similar projects, estimating what that would translate into once fired. The upside of work done like this is- it goes wherever it leads.
Downside is- it's wonderfully inefficient in terms of materials and time. But, the extra offcuts can be used to puzzle new designs while the additional time spent incubates whole new directions to pursue.
So, there is no downside.
