Red opaque pens (blocking UV light), alcohol-based, for preparing and retouching films before exposure. Ink is fast-drying and does not peel or crack after drying. It is permanent on non-porous surfaces like glass and metal allowing a use as a resist for etching (alcohol washable).
6 types of tips are available:
SF - super fine, 0,05mm (OP-005)
UF - ultra fine, 0,3mm (OP-330)
F - fine, 0,7mm (OP-220)
M - Medium 1,2mm (OP-100)
B - Broad chisel 3,5mm (OP-88)
BR - Brush (OP-55)