Thermal Hair is made from polypropylene fiber that changes color in reaction to changes in temperature.
Thermal Hair has a higher resistance to heat than kanekalon, but can still be sealed with a steamer and will melt under high, dry heat like a straightener/flat iron. Boiling water generally is not hot enough to seal it. It will not shrink when sealed, but will hold its shape once set.
If the ambient temperature of the room you're in is close to the point where the color changes, sometimes it will appear to get "stuck." You can get it to go back to the other color by exposing it to heat or cold (depending on what color it is and what you want to change to).
Thermal Hair cannot "burn out" - the fiber will never stop being able to change colors.
Length: 19" (48 cm) folded, 38" (96 cm) unfolded.
Weight: 0.78-0.88 oz (22-25 g) or 1.55-1.76 oz (44-50 g). All pictures and videos show the smaller 0.78-0.88 oz (22-25 g) size; the larger sizes is double that amount. Thermal hair comes in small packs that contain enough for a few braids, or for highlights/accents.
Texture: Straight. The strands are very fine and prone to tangling, so it's important to be careful and gentle when separating it. We do not recommend wearing thermal hair loose.
Color: Pale Pink/Yellow.
This color changes between pale pink and pastel yellow. The "warm" color is the yellow, so if it's pink and you want to change it, apply heat (like the heating pad in the video). If it's yellow and you want to change it back to pink, expose it to the cold (like the ice pack in the video).