Phenolic and Garolite are high temp resistant, very rigid, and mechanically stable. Often used for fixturing (think PCB bed of nails testing, soldering fixturing, etc.), housings, bearing linings, electrical insulators, etc. Can be machined, ground, sanded, etc. Think of phenolic as being similar to an epoxy resin with a paper or linen or other fabric filler in layers. Phenolic often has a "wood grain" appearance due to its color and the fabric layers used. It can be ground and polished to a glossy, attractive finish. Garolite usually has a "flour" filler added to the resin instead of the fabric, resulting in a more homogeneous appearance. Both are often overlooked by inexperienced engineers because they are thermoset materials (i.e., does not lend itself to high quantity injection molding like most thermoplastics) and are typically not used in very high quantity applications due to the type of processing required, but each has its place.