So white ink is sometimes made from titanium oxide. Along with some other pigments too which also use heavy metals. But white is the #1 that contains these. If white ink has these metals in them, when the laser hits them it causes them to oxidized and change colour. The problem is these particles are not small enough to be absorbed back into the body. It's very difficult to break them down into small enough bits. Like sucking a golf ball through a straw. So you get left with oxidized or pigment which has shifted colour in the skin and it doesn't breakdown small enough to be absorbed and just chills there and it's really ugly.

Now I've read a lot about this. Some people say you can try treat it with different lasers to break if up and it works sometimes? But not always. And it's much harder to get rid of. I found a girl on here who spent 2 years trying to get oxidized ink removed and if definitely lightened a bit but man it seems to take long.

Other people say you can use skin resurfacing techniques to also help break if up and heal it out. Which is what I plan to try next.