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.
NEMA G-10 MIL-I-24768/2 GEE, IPC 4101/20, IEC 60893-3 Type 2 EP GC 201
Grade NEMA FR-4 certs to MIL-I-24768/27 GEE-F, IPC 4101/21, IEC 60893-3 Type 2 EP GC 202

Standard Length 3 Feet

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.
NEMA G-11 certs to MIL-I-24768/3 GEB, IEC 60893-3 Type 2 EP GC 203; FR5 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.
NEMA G-5 MIL-I-24768/8 GMG , IEC 60893-3 Type 3 MF GC 201

NEMA G-9 MIL-I-24768/1 GME, IEC 60893-3 Type 3 MF GC 201

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.
X MIL-I-24768/12 PBM, IEC 60893-3 Type 4 PF CP 201
XX MIL-I-24768/11 PBG, IEC 60893-3 Type 4 PF CP 203
XXX MIL-I-24768/10 PBE, IEC 60893-3 Type 4 PF CP 201

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.
(Grade C certifies to Mil-I-13768/16 FBM, IEC 60893-3 Type 4, PF CC 201) 
(Grade CE certifies to Mil-I-24768/14 FBG, IEC 60893-3 Type 4, PF CC 203)

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.
NEMA L MIL-I-24768/15- FBI, IEC 60893-3 Type 4 PF CC 305
NEMA LE MIL-I-24768/13 FBE, IEC 60893-3 Type 4 PF CC 305