We have two formulas ourselves: A water-based and an alcohol-based formula. We can also make a xylene based formula if you wanted to.
Water-based is used mostly on textiles. They are also used on toilet seats to see if they have cleaned them.
Alcohol is permanent on non-porous surfaces anywhere they would want to go back and see the mark.
We can take a color (say a blue or red) and we we can put the uv base in the color. We can make it glow in the dark under black light. We can add this to any pen especially alcohol since when using alcohol we get better solubility than water.
As opposed to competing uv marker manufacturers, we can demonstrate a wide use of uv capabilities for paints.