Black hair can be relaxed, texturized, flat-ironed, stretched with Bantu knot outs or twist outs and blow-dried. The method to use depends on if the desired result is a temporary straightening or a more permanent look.
For permanent straightening, relaxers and texturizers are most effective, but because they use chemicals to straighten hair, they are also most damaging to the hair. For temporary straightening, Bantu knot outs and twist outs are the best at helping with curl pattern maintenance. However, because they are meant to help avoid damaging the curl pattern, they are less effective at straightening the hair. Blow-drying and flat-ironing have the advantage of being more effective for temporary straightening than Bantu knot outs and twist outs, and less damaging for permanent straightening than relaxers and texturizers.