A sterile, synthetic, implantable dye solution intended to be injected between the layers of the skin, using a tattoo needle and hand-held ink injector, for aesthetic pigmentation of the skin and visible mucous membranes. It is typically pH balanced for dermal applications and does not contain animal-derived materials. It may be implanted for a variety of reasons (e.g., for cosmetic decoration, to replace colour in the skin for patients affected by pigment deficiencies, for radiotherapy marking).