7 mm Gel Ink-pens exist in 27 different colors (the black and the blue are document proof only ISO 27668-2) and some of the colors can be bought as refills here: Pilot BLS-G2-7 Gel Ink 0

making it a sustainable choice for regular use

The 180 ml refill-bottle is perfect for those who work large areas and need a lot of paint

and Grog Black Magic Ink

which means that it will go perfectly with all types of markers and pens

parker jotter xl monochrome ballpoint pen black Painting on stones 7 mm Gel Ink-pens existThe Parker Jotter XL Monochrome Ballpoint Pen in Black takes everything you love about the classic Jotter and scales it up slightly for a more comfortable grip. The body and cap are finished in a sleek matte black, paired with the shiny signature arrow clip for a subtle contrast. Its lightweight, retractable, and opens with the familiar satisfying click. Inside, the Quinkflow ballpoint refill delivers smooth, consistent ink flow for effortless