Though ultimately the judgement of a pen’s performance is somewhat subjective, it’s important to understand the difference between the five most prominent pen categories and their respective ink types, so that you know which ones are most compatible with your writing style.
Ballpoint, rollerball, and gel pens typically all have a rolling ball mechanism at their tips, which distributes ink from their internal cartridge onto the page, but they all contain slightly different types of ink.
Ballpoint pens contain ink that is oil-based, and is the most viscous of all pen-ink types. This means that the ink dries quickly, but you may find yourself pressing down hard on the page in order to write with it.
Rollerball pens contain water-based ink, which allows them to glide far more smoothly over the page. This type of pen can be troublesome for left-handed people to use, however, since the ink is slower to dry and has the tendency to smudge.
Gel pens also contain a water-based ink, but this ink is pigment-based, rather than dye-based, so the consistency is slightly thicker than rollerball-pen ink. These pens are a little more user-friendly than rollerballs, and can also be found in a rainbow spectrum of colors. Cheap gel pens are prone to clumping and drying out, so this category of pen is worth spending a little more on.
Felt-tip pens are also known as marker pens, or porous-point pens, due to the porous material of their tips. These pens actually encompass a wide group of marker-type utensils, both permanent and nonpermanent, but the ones that are used for writing on paper contain a water- or pigment-based dye.
Fountain pens are sophisticated writing utensils that require a little more know-how to fill and use. They are typically used with dye-based inks, which are contained in disposable cartridges or in refillable converters. The tip of a fountain pen is called a nib, and the size of the nib affects the flow of ink from it. Though fountain pens can be used on regular paper, a thicker paper is recommended, because the pen’s higher output of watery ink is likely to bleed through a thin page.