The quality of synthetic wigs is now of top excellence, being visually indistinguishable from human hair, even for sharp-eyed experts. Synthetic wigs are easier to care for and are priced at a lower level. The mono-filament fiber "hair" used to make synthetic wigs have "memory", which means it maintains its wave or curl, texture and volume, requiring minimal upkeep. Synthetic wigs, however, are not designed to accept a permanent wave or “hair” dye, and can be permanently damaged by the use of curling irons, blow dryers or hot rollers.