FR-4 and G10 are National Electrical Manufacturers Association (NEMA) flammability grade designations assigned to products constructed of woven glass fiber laminate that is impregnated with an epoxy and flame retardants. Materials created under these designations are frequently used as printed circuit boards (PCB) and are often marketed under the name Garolite®. Laser processing FR-4/G10 is possible with a 9.3 or 10.6 micron CO₂ laser, with no significant difference between the quality produced by the two wavelengths. The 1.06 micron fiber laser is not used for cutting this material as the wavelength is not readily absorbed. Laser cutting of FR-4/G10 with a CO₂ laser produces a blackened carbonized edge that can be cleaned with a solvent. Laser marking of FR-4/G10 with a CO₂ laser carbonizes the surface of the epoxy creating a dark visible mark on a lighter surrounding substrate. Laser marking is also possible if there is a solder mask on the surface of the material, as the laser can ablate the solder mask to reveal the underlying epoxy or metal layer if present for a contrasting mark. Laser engraving is typically not recommended, as the process produces significant discoloration and deposition.