摘要 |
A process for evaluating the ionic state of the surface of keratin fibers, especially human hair, which comprises, taking at least one sample of fibers from the fibers to be evaluated, contacting the sample with an acidic solution of at least one acidic basic dyestuff, assessing what, if any, change in the color of the solution has taken place and attributing the ionic state to the surface of the fibers accordingly. |