I have been laser engraving for four years now but only doing tiles for 7+ months. I started without any paint then I heard of the NWT and it worked OK. But I hated the solvent part of it so I did some research. I looked up the data sheets for a more than a few paints and primers and came across this one, with TiO2 as it’s only pigment : https://www.rustoleum.com/-/media/DigitalEncyclopedia/Documents/RustoleumUSA/TDS/English/CBG/Zinsser/BEY123-01_Bulls_Eye_1-2-3_Water-based_Primer_TDS.ashx