Krink - Permanent Black Ink Mop - 4oz - Krink Permanent Black Ink Mop, a Krink original. The Krink 4oz Mop is filled with super black, opaque ink. The Krink Black Ink Mop has an extra large round nib and a massive 4oz capacity make this marker ideal for working in large areas. The Krink Permanent Black Ink Mop writes on most surfaces: excellent for use on metal, wood, canvas, painted surfaces, and paper. Krink Inks are of the highest quality. Handmade in the USA. Krink 4oz Mop bottles are recyclable (#2 resin code) HDPE plastic.