Red tattoo inks more than any other colour may cause severe allergy. Avoid red colours and red shades such as orange, pink, violet, burgundy, etc. These shades often contain red pigment combined with other pigments.
Have a tattoo that is as small as possible in tattooed area (the larger the tattoo, the more pigment in the skin, the greater the risk) and always on a place that can be covered by clothes. NEVER on the face, neck and hands, in many countries illegal because of the high risk of unforeseeable social disablement later in life. If possible, avoid the lower half of the arms and legs – if you regret the tattoo, summers will be rather hot wearing long sleeves or trousers! Or at least find a compromise if you really insist having a tattoo that will be visible and on display.
Avoid tattoos on the wrists and ankles. These cause more problems due to the function of the joints necessitating stretching the skin at joint motions.
Avoid those parts of the skin ("up sides") that are particularly exposed to the sun because sun-triggered problems are very common. Sunlight also breaks down the pigment to new chemical compounds which can cause allergy and problems. The sun over time make coloured tattoos bleach and even can change the colour from blue to dirty green, or white to black, for example.
Do not let the tattooist tattoo over brown moles because these can develop into melanoma, a highly malignant skin cancer. Melanoma may not be detected early enough if the tattoo pigment covers the mole. Delay in diagnosing melanoma can easily be fatal.
Demand that the tattooist uses only the amount of ink necessary, and not use excessive amounts of ink in the skin. Intensely coloured tattoos cause more problems.
Think twice about impulse tattoos including "party tattoos" and tattoos made under peers’ pressure. Say “No Thanks” and take time to consider. It is your skin, your life, your risk and your decision.
Choose your tattooist carefully. Make sure you know his right name; that hygiene is good; and that needles and gloves are only used once. The tattooist should be experienced and not an amateur – tattooing is a skilled craft that must be learnt. Never get a tattoo from a travelling tattooist including those who work at festivals. Avoid getting a tattoo abroad and particularly in countries where the incidence of penicillin-resistant staphylococci (MRSA) is high.
Ensure by yourself and insist that the ink bottles used for your tattoo are completely new and clean and from a generally recognised manufacturer. As a minimum, the manufacturer's name and full identity should be printed on the bottle which also shall have some form of declaration of ingredients especially a CI number, i.e. colour index number telling the chemical code of the pigment, which is then identified. Do not be tattooed with low-price ink, so-called "china ink", or copies of brand-name tattoo ink.
Sterile water should always be used for diluting ink and tattooing shadows - you can yourself buy sterile water at the pharmacy and take it with you. Distilled water is not necessarily sterile. Do never use water from the taps.
Always ask the tattooist for a slip stating the name, type and manufacture of the inks used on you, including the CI number. This is important if you develop a complication and need to consult a Doctor because of a tattoo problem. The tattooist does not keep personal records of customers – you must do this yourself by getting a slip. Store the slip safely somewhere. You can even take an I-phone photo of the ink bottle and the label. It is your assurance if an ink on the market is shown to have catastrophic effects and must be suddenly recalled from the market due to medical hazards coming up. Contaminated ink has been the cause of regional outbreaks. If anybody has had dangerous inks applied to their skin they need to report to a hospital to get early treatment in particular if high fever and symptoms of blood poisoning.