Which of the following inks should a tattoo artist avoid using?

A tattoo artist should avoid using inks with unknown chemical compositions because these inks may contain harmful substances or allergens that can adversely affect the client’s skin and overall health. Inks that have not been tested or properly labeled can lead to adverse reactions, infections, or complications during and after the tattoo process.

Using inks specifically labeled for skin use and those approved by the local health department generally ensures that the products are safe and formulated for human application. Tattoo artists have a responsibility to ensure the safety of their work, which includes choosing appropriate materials that meet health and safety regulations. Hence, avoiding inks with unknown compositions is crucial for maintaining the integrity of the tattooing process and the safety of the client.