A ballpoint pen dispenses an oil-based ink by rolling a small hard sphere, usually 0.5–1.2 mm and made of brass, steel, or tungsten carbide. The ink dries almost immediately on contact with paper. The ballpoint pen is usually reliable and comes in both inexpensive and expensive types. It has replaced the fountain pen as the most common tool for everyday writing. (There are certain ballpoint pens combining multiple colours in a single barrel; the writer or artist may depress the tip with the desired colour.)
A luxury ballpoint pen
A rollerball pen dispenses a water-based liquid or gel ink through a ball tip similar to that of a ballpoint pen. The less-viscous ink is more easily absorbed by paper than oil-based ink, and the pen moves more easily across a writing surface. The rollerball pen was initially designed to combine the convenience of a ballpoint pen with the smooth "wet ink" effect of a fountain pen. Gel inks are available in a range of colors, including metallic paint colors, glitter effects, neon, blurred effects, saturated colors, pastel tones, vibrant shades, shady colors, invisible ink, see-through effect, shiny colors, and glow-in-the-dark effects. Refillable rollerball pens have recently become available using cartridges of fountain pen ink.
A fountain pen uses water-based liquid ink delivered through a nib. The ink flows from a reservoir through a "feed" to the nib, then through the nib, due to capillary action and gravity. The nib has no moving parts and delivers ink through a thin slit to the writing surface. A fountain pen reservoir can be refillable or disposable; the disposable type is called an ink cartridge. A pen with a refillable reservoir may have a mechanism, such as a piston, to draw ink from a bottle through the nib, or it may require refilling with an eyedropper. Refill reservoirs, also known as cartridge converters, are available for some pens which use disposable cartridges. A fountain pen can be used with permanent or non-permanent inks.
A felt-tip pen, or marker, has a porous tip of fibrous material. The smallest, finest-tipped felt-tip pens are used for writing on paper. Medium-tipped felt-tips are often used by children for coloring and drawing. Larger types, often called "markers", are used for writing in larger sizes, often on other surfaces such as corrugated boxes, whiteboards and for chalkboards, often called "liquid chalk" or "chalkboard markers". Markers with wide tips and bright but transparent ink, called highlighters, are used to highlight text that has already been written or printed. Pens designed for children or for temporary writing (as with a whiteboard or overhead projector) typically use non-permanent inks. Large markers used to label shipping cases or other packages are usually permanent markers.
A gel pen uses ink in which pigment is suspended in a water-based gel. Because the 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 many types of writing and illustration. Gel pens often come in bright or neon colors.
A stylus pen, plural styli or styluses, is a writing utensil or a small tool for some other form of marking or shaping, for example, in pottery. It can also be a computer accessory that is used to assist in navigating or providing more precision when using touchscreens. It usually refers to a narrow elongated staff, similar to a modern ballpoint pen. Pens exist which contain a ballpoint tip on one end and this sort of touchscreen stylus on the other.
These historic types of pens are no longer in common use as writing instruments, but may be used by calligraphers and other artists:
A dip pen
A dip pen (or nib pen) consists of a metal nib with capillary channels, like that of a fountain pen, mounted on a handle or holder, often made of wood. A dip pen usually has no ink reservoir and must be repeatedly recharged with ink while drawing or writing. The dip pen has certain advantages over a fountain pen. It can use waterproof pigmented (particle-and-binder-based) inks, such as India ink, drawing ink, or acrylic inks, which would destroy a fountain pen by clogging, as well as the traditional iron gall ink, which can cause corrosion in a fountain pen. Dip pens are now mainly used in illustration, calligraphy, and comics. A particularly fine-pointed type of dip pen known as a crowquill is a favorite instrument of artists, such as David Stone Martin and Jay Lynch, because its flexible metal point can create a variety of delicate lines, textures and tones with slight pressures while drawing.
The ink brush is the traditional writing implement in East Asian calligraphy. The body of the brush can be made from either bamboo, or rarer materials such as red sandalwood, glass, ivory, silver, and gold. The head of the brush can be made from the hair (or feathers) of a wide variety of animals, including the weasel, rabbit, deer, chicken, duck, goat, pig, tiger, etc. There is also a tradition in both China and Japan of making a brush using the hair of a newborn, as a once-in-a-lifetime souvenir for the child. This practice is associated with the legend of an ancient Chinese scholar who scored first in the Imperial examinations by using such a personalized brush. Calligraphy brushes are widely considered an extension of the calligrapher's arm. Today, calligraphy may also be done using a pen, but pen calligraphy does not enjoy the same prestige as traditional brush calligraphy.
A quill is a pen made from a flight feather of a large bird, most often a goose. Quills were used as instruments for writing with ink before the metal dip pen, the fountain pen, and eventually the ballpoint pen came into use. Quill pens were used in medieval times to write on parchment or paper. The quill eventually replaced the reed pen.
A reed pen is cut from a reed or bamboo, with a slit in a narrow tip. Its mechanism is essentially similar to that of a quill. The reed pen has almost disappeared but it is still used by young school students in some parts of India and Pakistan, who learn to write with them on small timber boards known as "Takhti".