For the WET & WAVE hair such as the French Refined, you may test the wave by wetting a small portion away from the rest. Place the hair on a desk, a small portion away from the rest, spray some water(90%) and conditioner(10%), and let it soak for about 15 seconds. Hold the top of the hair while it is on the desk and gently brush the wet portion from the bottom and watch it wave. Towel dry and scrunch it to wave up more. Blondes / lighter / mixed colors go through more excessive processing than darker colors. Therefore, the wave and condition may not be as good.