ZIG Illumigraph markers are available in 8 fluorescent colors reactive to Ultra Violet light. Illumigraph markers are a water-based pigment, hi-opaque, odorless and easily erases from non-porous surfaces with water. Suitable surfaces include; blackboards, whiteboards, glass, metal, plastic, paper, and wood. Available in bullet point tip, chisel, and flat up to 50mm. Use glass cleaner for easy removal.