Layer upon layer - creating glass cane with coloured fritAs in many creative processes, planning is critical and a sketch of the finished product can guide the work. Building the cane starts with a gather of molten glass, either clear or coloured depending on the desired colour of the core. The punty (metal rod) is dipped into the clear molten glass then rolled on a marver to smooth it.
The next step is to roll the glass in coloured frit, which is finely ground glass. In this example we are using pink frit to create the second layer. The process of adding clear glass then rolling in coloured frit can be continued until the desired number of layers has been achieved. The final layer may be coloured or clear glass. By this time the glass can be several inches in thickness. We’ll talk about stretching the cane later.
Building layers using glass colour potsAnother method of creating cane is using pots of molten coloured glass rather than frit. This photo shows the punty being dipped into one of the colour pots. The glass will be rolled on a marver to achieve a uniform thickness before being reheated in the glory hole and dipped in another pot of colour.
The process of dipping into colour, rolling and reheating is repeated depending upon the design. The final thickness of the glass can be 6-8 inches or more.
Although all pots in the photo appear to be the same colour, that is because of the intense heat. The colours are actually red, white, black and green.
Shaping the caneOnce the final sequence of colour has been added, the glass is inserted into a multi-pronged metal frame which creates indentations. Using a blade, the lines are deepened to exaggerate the indentations – this distortion actually creates a 6-petal flower design when the cane is stretched.
From thick glass rod to thin glass caneAnd now the stretching begins, usually requiring a second glass blower. The thick mound of glass is reheated in the glory hole then joined to a knob of clear glass on another punty controlled by the second glass blower. Glassblowers Chago and Sean work together as they raise one punty and lower the other, letting gravity assist in the stretching.
The finished cane must be less than an inch in diameter so the glass blowers will quickly walk away from each other until they are forty to fifty feet apart. By then the glass has started to cool and is laid on the floor in one long strip. The cane is then cut into 2-3 foot lengths and quickly placed in the annealing oven where it will cool down slowly overnight.
Murrine - the finished productThis composite photo takes us through the last stages. The brightly coloured finished canes are about 3 feet long. At this stage they are cut into murrine, thin slices about 1/8 to 1/4 inch in diameter. Glass snips or a saw are used, revealing the intricate internal design. The murrine are now ready to be used in the Robert Held Flower Bouquet vases and bowls, a topic for another blog.
Robert Held's beautiful art glass vessels, such as this teardrop shaped vase with Flower Boouquet murrine, can be purchased in the gallery or in our online store www.robertheld.ca