Petroleum Jelly

You may have noticed that some artists will use a light coat of
petroleum jelly on the tattoo after applying the stencil prior to
outlining. However, it is very important that you use very little petroleum
jelly. What the petroleum jelly does is it relieves friction
that is created when your dragging glove is rubbing the skin. It
will also help capture the excess pigment after a stroke is made.
By capturing the excess pigment that is left over from the tip of
the tube while the stroke is made, it will make for an easier time
to see where you are at while lining.