Spalted (also spelled Spaulted) Bowls The beautiful spalting effect of the Peterman bowls is actually a by-product of a process that is carried out by mold and decay fungi that are found naturally on the forest floor. The fungi create zone lines in the wood where territories of competing fungi meet. When the temperature and humidity are right, spalting can cause many different and beautiful patterns in the wood. The unusual coloration may be due to chemically induced reactions between the wood, fungi and insect deposits, often resulting in black, pink, gray and multicolored streaked wood. Hidden in the moss and dirt covered trees are special features that Spencer Peterman brings to life with the lathe in his wood shop. In particular, the fungus behind the wood's transformation leaves behind a marbled appearance and bold, black lines that form graphic patterns for the spalted bowls. The trick is to work the wood at just the right time, before decomposition has gone too far. Burl Bowls Cherry Burl Bowls Burls are fast growing abnormal growths on a tree. They are caused by environmental stress, damage, or disease (fungal or insect attack) on the tree. The type of burl preferred by our woodworkers is the type that grows in wild irregular swirling patterns with "eyes". The twisted and multi-directional grain of the burl gives a fascinating activity to the surface of the wood. Burls usually come from large knob-like projections along the tree trunk. These irregular growths are sometimes caused by a fungus. Very twisted and irregular growth patterns are also obtained from the roots of trees.