The Ecco Pigment Pens were invented to replace the TG1 Technical Drawing Pens. They are used for slow and precise drawing. The long metal-clad tip is ideally suited for rulers and stencils. The ergonomic shape of the Ecco Pigment Pen ensures tireless writing. The water-based inks are fast-drying, lightfast, document-proof and waterproof on paper and will not bleed through. The mark is deep black on office and parchment paper. They are erasable on transparent paper. The cap and barrel are made from Eco Plastic and the clip is nickel-free metal. They are ideal for writing, drawing and sketching.