limit of approximately 4000 substances when contained in tattoo inks. According to a study by the European Union Observatory for Nanomaterials (EUON), a number of modern-day tattoo inks contain nanomaterials. These engender significant nanotoxicological concerns. Certain colours – red or similar colours such as purple, pink, and orange – tend to cause more problems and damage compared to other colours. Red ink has even caused skin and flesh damages so severe that the amputation of a leg or an arm has been necessary. If part of a tattoo (especially if red) begins to cause even minor troubles, like becoming itchy or worse, lumpy, then Danish experts strongly suggest to remove the red parts. In 2017, researchers from the European Synchrotron Radiation Facility in France say the chemicals in tattoo ink can travel in the bloodstream and accumulate in the lymph nodes, obstructing their ability to fight infections. However, the authors noted in their paper that most tattooed individuals including the donors analyzed do not suffer from chronic inflammation. Tattoo artists frequently recommend sun protection of skin to prevent tattoos from fading and to preserve skin integrity to make future tattooing easier. Removal While tattoos are considered permanent, it is sometimes possible to remove them, fully or partially, with laser treatments. Typically, carbon based pigments, or iron-oxide-based pigments, as well as some colored inks can be removed more completely than inks of other colors. The expense and pain associated with removing tattoos are typically greater than the expense and pain associated with applying them. Methods other than laser tattoo removal methods include dermabrasion, salabrasion (scrubbing the skin with salt), reduction techniques, cryosurgery and excision—which is sometimes still used along with skin grafts for larger tattoos. These older methods, however, have been nearly completely replaced by laser removal treatment options. Temporary tattoos A temporary tattoo is a non-permanent image on the skin resembling a permanent tattoo. As a form of body painting, temporary tattoos can be drawn, painted, or airbrushed. Types Decal-style temporary tattoos Decal (press-on) temporary tattoos are used to decorate any part of the body. They may last for a day or for more than a week. Metallic jewelry tattoos Foil temporary tattoos are a variation of decal-style temporary tattoos, printed using a foil stamping technique instead of using ink. The foil design is printed as a mirror image in order to be viewed in the right direction once it