Glass is produced in furnaces that heat up to over 2000 degrees fahrenheit. When a glass blower "gathers" glass on their pipe, the material is so hot that it can drip like a liquid. This is why you always see glass blowers spinning their pipes - centrifugal force keeps the liquid-like glass from dripping off. They spin their blowing pipes into the glass furnace to gather glass that ultimately is formed into array of different shapes. The demonstration above shows Pierre getting a gather of glass from the furnace, which melts a recipe of glass ingredients together to form workable glass. Right away a glass blower creates a bubble within the first gather of glass. By blowing into the pipe and trapping air and forming a bubble much like a chewing gum bubble.
Once the first gather is picked up onto a glass blower's pipe, shaping the piece to be transferred onto a "punty" is next. To do this a glass artist uses tools such as blowing air through the pipe, a marver, blocks, jacks, and wooden paddles. In the video, you see Pierre using the marver (the steel table) to cool the glass so the initial bubble blows out centered. You see him using the blocks, to set a foundational shape for his piece to form from. Lastly, you see him using jacks to create a jack line to knock off the piece onto a punty.
THE PUNTY TRANSFER
Glass blowers transfer glass pieces onto a punty pipe in order to form and finish the shape of their intended artwork. Because Pierre is making a cup in this video, he needs to transfer the glass to a punty pipe to form the lip of the cup. The punty process involves an assistant preparing a little bit of glass to connect to the glass piece. Once the punty is prepared, you see Pierre connecting the punty pipe to the glass piece and then knocking off the glass piece onto the newly connected punty pipe.
Last but not least is opening the piece up. When the punty transfer is complete, the once enclosed bubble inside the glass is now exposed. The newly attached punty has allowed Pierre to now form and open up the glass. He uses jacks that enter inside the exposed bubble to stretch the bubble to open up into the shape of a cup. When Pierre is happy with the shape of the piece, he then knocks it off to place in the annealer. The annealer cools the hot glass piece slowly to avoid shock and potential cracks.