With their waterproof aprons and big rubber gloves, the women hanging wet pieces of fabric out to dry look as though they are taking part in a busy wash-night before the invention of washing machines.
But a closer look reveals that the fabrics are all silk and the large tubs contain not soapy water but dyes of turquoise, yellow, burgundy and aqua-marine.
"Using brushes dipped in hot wax we block out areas of the silk," explains tutor Melanie Brickley, "and the part with the wax then resists the dye. When I was making one of a curling pond on Cumbrae I blocked out the clouds and the white cottage, then dipped it in the palest turquoise, dried it and stretched it. Then I waxed the sky so it would remain turquoise and dipped it again in a different colour.
"For a decent picture you might add colour and depth, building layer upon layer, by dipping the silk as many as 50 times."
The craft called batik originated on the island of Java, where artists still use a tjanting, a little copper pot containing hot wax, with a wooden handle attached to one side and a spout at the other, to sketch intricate designs on silk before dipping it in dye.
Batik can produce spectacularly beautiful results, and the complex process appeals to a certain type of mind. "It's very challenging," says Ms Brickley. "It hooks you and fires your imagination."
Teacher Hazel Blane, who is trying the craft for the first time, says:
"It's tricky but absolutely fascinating. You have to work out which bits to block out, then which colours will go together to make the ones you want. I like crafts like this that are precise and take time and you have to think about them. I'd love to try it at home but you'd need a whole room to work in."
This class was held at the Aldessan Gallery, Clachan of Campsie, Campsie Glen, Glasgow G66 7ABTel: 01360 313049