The making of "Mudra (Girl in a Blue Dress)"

So much for the history of glass. How do I create a fused glass platter? Here is the process for “Mudra (Girl in a Blue Dress) that I made for the Spirit exhibition at the TAP Gallery in April 2011.

First comes the design – the aesthetic proposal if you will. I try to incorporate the guidelines of repetition, variety, rhythm, balance, emphasis, economy and proportion (the design principles as set out in “Shaping Space” by Zelanski and Fisher).

The final panel or plate is made up of two fused layers of glass, the bottom layer a single sheet of clear (Spectrum) System 96 glass and the top layer made up of pieces cut from sheets of both transparent and opaque glass. The girl’s dress is cut from a pattern called blackberries and cream. The glass in both layers must have the same coefficient of expansion. System 96 has a COE of, not surprisingly, 96 while Bullseye glass has a COE of 90. Mixing COEs just means a cracked and often irreversibly damaged piece.

The cut pieces of glass must fit closely together so some may have been ground or shaped after cutting. The glass is held in place with Glastac glue or (cheap) hair styling spray. Trust me, it works really well.

The glass must be really clean to avoid imperfections after firing.

The two assembled layers are placed on ceramic fibre paper on a kiln washed shelf. I am over cautious and could do one or the other but prefer to take no chances, as there are enough things that can go wrong! Glass tack or partially fuses at 730 - 760°C and fully fuses creating one uniform glass layer at 790 - 835°C. This piece is full fused with the following schedule; 60 minutes to 540°C then 30 minutes to 620°C and hold for 60 minutes. Thirty minutes to 810°C, hold for 30 minutes then rapid cool as fast as possible to 560°C and hold for 105 minutes, down to 440°C over three hours and then end programme. That’s an 8 ½ hour fusing schedule and then about another 8 hours of nervous waiting before the kiln can be opened.

The firing programme is in several parts – initial and gradual heating through the strain point then more rapid heating through the softening point to the working temperature followed by rapid cooling down through the devitrification range and finally slow maintenance cooling to ensure the glass anneals correctly.

Once fused the glass piece in this case is framed for gallery display. More often than not the fused piece will be slumped into a mould for a further 8 – 10 hours of kiln time and the final piece will be a functional platter for everyday use and a beautiful work of art to be displayed.