Scalp pigmentation.i am having long hairs but some parts have thin down so i am plannig to go for scalp pigemntation?could you please advice me on this.and is partial hair transplant possible?The pigment consists of Iron Oxide, which according to the clinics is readily present in the body naturally The main difference between a tattoo and SMP is that SMP is semi-permanent and uses a completely natural pigment. It uses specialist pigments created for the scalp only, not tattoo ink.is it true