Uni-Paint 63735 PX-30 Oil-Based Permanent Marker, Bold Line, Yellow, 6-Pack
Does not contain sulfur, silicon, etc. Waterproof even after writing. Ink doesn’t run even when used surface is heated. PX-30, Bold line, yellow. Ink is permanent and certified AP-non-toxic. Oil-paint ink is fade, water, and abrasion-resistant.