The Birchwood Casey Universal Touch Up Pen is a specially formulated, super permanent ink that you can use on nearly all materials for touch up or as a permanent marker. For firearms applications like blued steel and black anodized aluminum, the industrial formula remains permanent against most solvent/ chemical washes.
Specifications and Features:
Resists bleeding and fading when exposed to heat, light, steam, and most solvents
Deep black color works on both gloss or matte surfaces