Having used Rapidograph technical drawing pens forever, I finally switched to the disposable little Sakura’s Pigma Micron pen and love it. Bob Mankoff, cartoon editor of the New Yorker, draws all his pointillistic funnies with one. It costs a mere $2.98, as opposed to $25+ for a Rapidograph. Micron pens come in an array of point/line widths: #005 (0.20mm), #01 (0.25mm), #02 (0.30mm), #03 (0.35mm), #05 (0.45mm), #08 (0.50mm) points.
If you have never tried a Micron pen, you can buy a 6-Piece Sampler Pen Set in Black so you can test the point size(s) that suit you best.
Sally says she can’t write with anything else. She says her writing looks “cooler”, and it feels great in her hand. Her favorite is the 01/0.25-mm Micron in black.