The Staedtler 308 Pigment Liner Pen is a precision, German made fineliner pens for writing, sketching and drawing. They feature a long metal tip, ideal for use with rulers and templates. these pens contain pigment ink which is indelible, lightfast and waterproof. They are erasable when used on drafting paper and do not bleed when highlighted. They Can be left uncapped for 18 hours without drying up (Standard atmosphere according to ISO 554). The ink is a very deep black.