Phenolic Thermoset Plastic Laminate. Phenolics are a uniformly dense and structurally strong material that will not soften appreciably under the reapplication of heat. It is an extremely durable plastic that is lightweight and moisture resistant. Industrial laminates are thermoset resin impregnated reinforcing materials (paper, cotton fabric, glass fabric, etc.) that are cured under heat and pressure to form solid shapes having high mechanical and electrical insulating properties. Laminates are available in sheet, rod, tube, and angle. Since laminates are comprised of a combination of materials, they are also referred to as composites. Phenolic standard stock grades include:

G10/FR4 Glass Reinforced Epoxy - natural (yellowish to light green) Technical Data Sheet   
The most versatile all-around laminate, this grade is a continuous glass woven fabric base impregnated with an epoxy resin binder. It has extremely high mechanical strength, good dielectric loss properties, and good electric strength properties, both wet and dry.
Certifies to Mil-I-24768/27 GEE-F

G11/FR5 Glass Reinforced Epoxy - natural (yellow green to amber) Technical Data Sheet
This grade is similar to G10/FR4, with the addition of a higher operating temperature and some improved mechanical strength at elevated temperatures.
Certifies to Mil- I-24768/28 GEB-F

G5/G9 Glass Reinforced Melamine - natural (grayish brown) Technical Data Sheet
This grade is composed of a continuous glass woven cloth base impregnated with a melamine resin binder. Melamines are the hardest of all laminates, exhibiting good dimensional stability and arc resistance. It is also caustic resistant.
Certifies to Mil-I-24768/1 GME

G7 Glass Reinforced Silicone - natural (cream to white)

Technical Data Sheet
Composed of a continuous glass woven cloth base impregnated with a silicone resin binder,this grade has excellent heat and arc resistance. It has extremely good dielectric loss properties under dry conditions and good electrical properties under humid conditions, although the percentage of change is high.
Certifies to Mil-I-24768/17 GSG

Paper X/XX/XXX Paper Reinforced Phenolic - natural (tan) Technical Data Sheet
This grade is composed of a paper base impregnated with a phenolic resin binder. It has good electric strength properties with fair mechanical strength. Outstanding for use as template material and or backup material.
Certifies to Mil-I-24768/12 PBM, /11 PBG and /10 PBE

Canvas C/CE Cotton Fabric Reinforced Phenolic - natural (light tan to brown) Technical Data Sheet
This grade is composed of a continuous cotton woven cloth impregnated with a phenolic resin binder. This grade contains a medium weave canvas and is known primarily for it's mechanical properties. This grade is not recommended for primary insulation.
Certifies to Mil-I-24768/14 FBG

Linen L/LE Cotton Fabric Reinforced Phenolic - natural (light tan to brown) Technical Data Sheet
This grade is composed of a continuous cotton woven cloth impregnated with a phenolic resin binder. This grade contains a fine weave linen and, like the canvas phenolic, is known for it's mechanical properties. The finer weave allows for machining more intricate details than Canvas, like gear teeth. This grade is not recommended for primary insulation.
Certifies to Mil-I-24768/13 FBE