Generally, heated styling appliances can be used ONLY on 100% human hair extensions. Use conditioning whenever possible. Always do a test curl first and use the lowest effective temperature level (about 180 degrees). Overuse of curling irons, flat irons and blow dryers will shorten the life of human hair extensions. Heated curling or straightening irons should never be used on synthetic hair.
Tips for dyeing hair extensions:
We all know that 100% human hair extensions can be dyed. The perfect hair type for coloring is the virgin hair extension also called virgin Remy hair extensions. This type of hair would have never been chemically-processed before you receive them and hence should be ideal for dyeing. Coloring of virgin hair extensions is much like doing them for natural hair and a lot of care must be taken to protect them from harsh chemical agents. Most other types of hair, especially synthetic hair, are unsuitable for dyeing as they tend to become really weak due to exposure to chemicals. Dyeing them will irreversibly damage your hair extensions. Again, strand testing is the best method to prevent damage from dyeing.
Tips for bleaching hair extensions:
Lightening is more difficult and riskier than darkening. Lightening usually requires bleaching hair extensions which can really damage them - even 100% human hair extensions. To avoid bleaching, you can directly dye the darker hair into the color you desire, but that usually leaves a tint of dark shade. The hair ends up with shades of slightly orange. However, re-doing the coloring over and over again should remove the orange shade and eventually get you to the light color that you had wanted. Usually you'll need three processes to obtain the perfect match. Colorings will have to be repeated in intervals of a few days.