Skin whitening cells causes the skin to naturally regenerate itself. Excess melanin comes to the surface and peels off in a few days. This is particularly useful in sensitive areas like the genitals where laser treatment could leave a scar. Efficacy of the treatment depends on the depth of the pigment. There is evidence to suggest that some types of skin-whitening products use active ingredients, such as mercurous chloride and hydroquinone, which can be harmful. Hydroquinone is not available without a prescription in Europe. It is only available when prescribed by a medical doctor (e.g. a general practitioner). This is also the
Chinese pigment Chinese pigment Chinese pigments () are the traditional medium to execute traditional Chinese brush paintings, besides ink. Chinese pigments is similar to Western gouache paint in that it contains more glue than watercolours, but more so than gouache. The high glue content makes the pigment bind better to Chinese paper and silk as well as enabling works of art to survive the wet-mounting process of Chinese hanging scroll mountings without smudging or bleeding. Traditionally, Chinese pigments come in form of chips, cakes or powder made from natural plant and minerals. Some of these require preparation by adding glue (明膠) before