A pen is a common writing instrument that applies ink to a surface, usually paper, for writing or drawing. Early pens such as reed pens, quill pens, dip pens and ruling pens held a small amount of ink on a nib or in a small void or cavity which had to be periodically recharged by dipping the tip of the pen into an inkwell. Today, such pens find only a small number of specialized uses, such as in illustration and calligraphy.

Read about Pen and its different types by Pritish Kumar Halder article.

Reed pens, quill pens and dip pens, which were used for writing, have been replaced by ballpoint pens, rollerball pens, fountain pens and felt or ceramic tip pens. Ruling pens, which were used for technical drawing and cartography, have been replaced by technical pens such as the Rapido graph. All of these modern pens contain internal ink reservoirs, such that they do not need to be dipped in ink while writing.

Types

Modern

1)A ballpoint pen dispenses a viscous oil-based ink by means of a small hard sphere, or ball, which rolls over the surface being written on. The ball is held captive in a socket at the tip of the pen with one half exposed and the other half immersed in ink from the pen’s reservoir. When the ball rotates, it transfers the ink – which wets the ball – from the reservoir to the external surface.

2)A gel pen works similarly to a ballpoint pen, in that it dispenses ink using a rolling ball held in the writing tip. However, unlike oil-based ballpoint pen ink, gel pen ink consists of a water-based gel that has a pigment suspended in it. 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.

3) A rollerball pen is a pen that dispenses a water-based ink through a ball tip similar to that of a ballpoint pen. As such, gel pens might be considered a subcategory of rollerball pens; however, due to the widespread knowledge and use of the term ‘gel pen’, ‘rollerball’ is in practice typically reserved for pens which use liquid ink.

The lower viscosity of rollerball ink compared to oil-based ballpoint pen ink has several effects on the pen’s performance. Since the ink flows more easily and is more easily absorbed into paper, more ink is dispensed in general. This changes the writing experience by lubricating the motion of the tip over the paper.

4) A fountain pen uses water-based liquid ink delivered through a nib, which is in general a flat piece of metal with a thin slit extending inwards from the writing tip. Driven by gravity, the ink flows from a reservoir to the nib through a feed, which is in general a specially shaped solid block of material with channels and grooves cut into it. The feed delivers the ink to the slit in the nib. While writing, ink is pulled out of this slit by capillary action.

5) A felt-tip pen, or marker, has a porous tip made of fibrous material, which normally remains saturated with ink from the reservoir. As ink leaves the tip, new ink is drawn from the reservoir – which often consists of a large volume of a similar porous material to that used in the tip – by capillary action and gravity. As with a fountain pen, ink leaves the tip of a felt tip pen by capillary action when writing on a porous surface. However, unlike fountain pens, many markers can also reliably write on slick impermeable surfaces that are wet by the ink, and in such applications ink typically does not continually leave the pen as it is held against the writing surface.

6) A brush pen is a pen whose writing tip consists of a small brush fed with ink from a liquid ink reservoir similar to those used in fountain pens and rollerball pens. Brush pens might be either refillable or disposable, and might use either water-based or waterproof ink. The most significant functional difference of brush pens from felt-tip pens is the far greater compliance of the tip.

Brush pens are an obvious alternative to ink brushes for Chinese calligraphy and Japanese calligraphy, but are now also commonly used in other forms of calligraphy and by artists such as illustrators and cartoonists. The primary appeal of these pens to such artists is that they allow a great deal of line width variation in response to small changes in applied pressure.

7) A stylus pen, plural styli or styluses, is a writing utensil which does not use ink, but rather makes marks primarily by creating scratches or indentations in the writing surface. As such, the tip often consists simply of a sharp metal point. Such tools are also used for other types of marking than writing, and for shaping or carving in, for example, pottery. The word stylus also refers to a pen-shaped computer accessory that is used to achieve greater precision when using touchscreens than generally possible with a fingertip. There are products available that combine a ballpoint tip at one end and a touchscreen stylus at the other.

Historic

These historic types of pens are no longer in common use as writing instruments, but may be used by calligraphers and other artists:

1)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 is called such because it usually has no ink reservoir and must therefore be repeatedly dipped into an inkpot in order to recharge the nib 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 so-called 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.

2) The ink brush is the traditional writing implement in East Asian calligraphy. The body of the brush can be made from bamboo, or from 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, and tiger. There is also a tradition both in China and in Japan of making a brush using the hair of a newborn, as a once-in-a-lifetime souvenir for the child.

3) A quill is a pen made from a flight feather of a large bird, most often a goose. To make a quill, a feather must be cured through aging or heat-treatment, after which a nib is fashioned from the shaft by cutting a slit in it and carving away the sides to create a pointed tip.

4) A reed pen is cut from a reed or bamboo, with a slit in a narrow tip. Its mechanism is essentially the same as that of a quill or a metal dip pen. The reed pen has almost disappeared but 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”.

Reference

https://en.wikipedia.org/wiki/Pen