Marker pen in the context of "Crayola"

A pen is a common writing instrument that applies ink to a surface, typically 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 that 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. Reed pens, quill pens and dip pens, which were used for writing, have been replaced by ballpoint pens, rollerball pens, fountain pens and felt or ceramic tip pens.

Ruling pens, which were used for technical drawing and cartography, have been replaced by technical pens such as the Rapidograph. All of these modern pens contain internal ink reservoirs, such that they do not need to be dipped in ink while writing.

Caran d'Ache (French pronunciation: [kaʁɑ̃ daʃ]) is a Swiss manufacturing company of art materials and writing instruments. The company, established in 1915, produces a wide range of products including colored pencils, graphite pencils, pastels, fountain pens, ballpoint pens, mechanical pencils, markers, gouache paints, and ink cartridges.

A sketch (ultimately from Greek σχέδιος – schedios, "done extempore") is a rapidly executed freehand drawing that is not usually intended as a finished work. A sketch may serve a number of purposes: it might record something that the artist sees, it might record or develop an idea for later use or it might be used as a quick way of graphically demonstrating an image, idea or principle. Sketching is the most inexpensive art medium.

Sketches can be made in any drawing medium. The term is most often applied to graphic work executed in a dry medium such as silverpoint, graphite, pencil, charcoal or pastel. It may also apply to drawings executed in pen and ink, digital input such as a digital pen, ballpoint pen, marker pen, water colour and oil paint. The latter two are generally referred to as "water colour sketches" and "oil sketches". A sculptor might model three-dimensional sketches in clay, plasticine or wax.

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 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.

The general design of a gel pen is similar to that of a regular ink-based pen, with a barrel containing the writing mechanism and a cap, and a reservoir filled with ink. At the end of the ink tube is an ink "follower", made of more viscous gelled material which is usually translucent and follows the water-based ink. The follower mainly prevents leakage and back flow of the ink.

A permanent marker or indelible marker is a type of marker pen that is used to create permanent or semi-permanent writing on an object.

Sakura Color Products Corporation (株式会社サクラクレパス, Kabushiki-gaisha Sakura Kurepasu) is a Japanese manufacturing company headquartered in Morinomiya-chūō, Chūō-ku, Osaka, which produces a variety of stationery products as well a wide range of art materials. Nevertheless, Sakura is mostly known by its marker pens, such as the Pigma line.