The skin/ pigment relationship: The color interacts with the skin during the first month after the procedure. You will see the final result after that, so don't do any touch ups before one month, even if you don't see color or the color looks weird. If after a month you don't see any color or the color is lighter that the desired color, you need to do a touch up, and that is completely normal.
There are very rare cases where the client's immune system does not accept the pigment, rejecting it completely, and no matter how many touch ups you make or which technique you use, you will never see pigment on his or her skin.
It is important that your client knows this during the consultation in order to avoid any complains.
The after care is very important.
Please read the After care instructions for your clients
blog entry. People who are highly exposed to the sun, chlorine or salt water, glycolic or retinoic acid among other, may eliminate the color faster than people who are not.