Tombow Mono Drawing Pens 3pk Black Waterproof Pigment Ink for Watercolor Painting (01, 03, 05 sizes)
Tombow Mono is my go-to disposable fineliner for drawings that will be painted over later. It is waterproof and lightfast, it dries very quickly so I can move on to watercolor painting after a few minutes. This is a set of 3 pens including a very fine 01 size, medium 03 and bold 05. I use the 01 pen for small line detail on almost all of my small watercolor paintings drawn on artist trading cards or 5x7" size.
Like all disposable fineliner pens (such as Uni Pin, W&Newton, Micron's non PN version etc.) it has a very fine felt tip in a tiny metal needle tube, which can be worn down by pressure when drawing. When using fineliners on textural cold pressed watercolor papers I recommend a slow and light touch to help avoid needle drag on the dips and valleys of paper, and to help your pen be able to complete a few drawings with the most precision. For non-disposable options I recommend a technical pen like Rotring Isograph and R&K's Sketch Ink bottles, but those require more maintenance, can leak and have to be cleaned out between 1+ week storage so I only suggest them for highly active artists blowing through a lot of disposables. I talk more about pens, brushes and other watercolor related supplies on this page.