Do you want a fine line, thick line or something in between? This is determined by the “point size,” which refers to the diameter of the nib, or tip, of a pen. The sizes are listed in millimeters, and the lower the number, the finer the line. For example: 0.5mm is somewhat fine, 0.7mm is the most commonly used, and 1.6mm is quite bold.

This is just another way of saying capacity, or life expectancy, of the pen and indicates how long can you write with a particular pen before the ink cartridge runs out.

Describes how much ink flows out and is applied to the writing surface when writing. As you might guess, the bolder the line (higher point size), the greater the amount of ink is laid down.

Just what you think: the amount of time it takes for ink to dry on the writing surface. Pens that lay down a lot of ink (see above) take longer to dry. Other factors that lengthen Dry Time are: the type paper used, the amount of pressure applied by the pen user, and type of ink. Metallic inks tend to dry more slowly. Most people want ink that dries pretty fast.

If you remember your science class, you know that fluid viscosity refers more or less to the thickness of a fluid, and in pens, it refers to how easily and smoothly the ink flows from the pen. You want a low viscosity ink to get the smoothest writing experience.