Markal Paintstik Markers are real lead-free paint in stick form. From extreme cold environments (-50 F) to High-heat work applications (2200 F), Markal Paintstiks are suitable for any surface that is smooth or rough, clean or oily. Solid Paint-Ambient Surface Markers : B - Marks any Material or Surface. B-E - For Marking Very Rough Surfaces. B-L - Bleeds Through Solvent-Based Paints. BL-W - Bleeds Through Water Based Paints. C - For Marking on Smooth Surfaces. E - For High-Visibility Marks. F - All Purpose Fluorescent Marker. Fast Dry -Dries in 5 Minutes. M - Marks Annealed, Normalized & Heat Treated Surfaces. N - Marks Will Not Show Through Top Coat. O-10 - Marks Heavily Oiled Surfaces. P - Removes in Pickling Bath. WS -Water Soluable.