Q. A woman that became a baalat teshuvah and she has a tattoo that she is planning to remove or change, is it meantime a chatzitzah?

A. Poikim rule that stains that have no substance to them, and they just present a superficial coloration of the skin, such as an iodine or a weak ballpoint stain, on the onset they should be removed when possible. (Har Tzvi Y.D. 163, Pische Zuta 198: 26, Shiurey Shavet Halevy 198: 17, Chut Shani 198: 23, Pischei Halocho 2: 296)

However in regards to tattoos, Horav Shlomo Miller’s Shlit’a opinion is that she is permitted to immerse without having them excised, since the stain is under the skin.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit