38 is made with a very traditional technique called “balloton”. For this technique, the master glassmaker uses a special metal mould which has small pyramid-shaped tips with a square base all along the interior surface of its circumference.
During the blowing process, the glass entirely fills the empty spaces in the mould and creates a particular optical effect of crossed relief.
29 is created by blowing a glass bubble inside an aluminun net. In contact with the hot glass, the aluminum melts creating bubbles and leaving shiny residues.