22690 Capybara Stack Gel Pen-36 Smooth fine tip black gel ink. $1.25, $45 a display of 36 pens. BCmini gel pen uses a gel-based ink, combining the permanence of oil-based ballpoint ink and the smooth glide of water-based ink, in which pigment is suspended in a water-based gel. Gel ink is thick and opaque, it shows up more clearly on dark or slick surfaces than the typical inks used in ballpoint or felt tip pens. Gel pens can be used for varies types of writing and illustration. Fine-tip gel pens let you fit more writing onto every page and card. They make your handwriting neater by creating sharper, more consistent lines. As they don’t put as much ink on the page as broader pens, they dry faster and are less prone to smudging.