Marker pens

A marker pen, fineliner, marking pen, felt-tip marker, felt-tip pen, flow, marker or texta (in Australia) or sketch pen (in India), is a pen which has its own ink-source, and a tip made of porous, pressed fibers such as felt. A permanent marker consists of a container (glass, aluminum or plastic) and a core of an absorbent material. This filling serves as a carrier for the ink. The upper part of the marker contains the nib that was made in earlier time of a hard felt material, and a cap to prevent the marker from drying out. Until the early 1990s the most common solvents that were used for the ink were toluene and xylene. These two substances are both harmful and characterized by a very strong smell. Today, the ink is usually made on the basis of alcohols (e.g. 1-propanol, 1-butanol, diacetone alcohol and cresols). Markers may be waterproof, dry-erase, or permanent which will be further expanded on in this article.

Lee Newman patented a felt-tipped marking pen in 1910. In 1926, Benjamin Paskach patented a "fountain paintbrush" as he called it which consisted of a sponge-tipped handle containing various paint colors. Markers of this sort began to be popularized with the sale of Sidney Rosenthal's Magic Marker (1953) which consisted of a glass tube of ink with a felt wick. By 1958, use of felt-tipped markers was commonplace for a variety of applications such as lettering, labeling, and creating posters. The year 1962 brought the development of the modern fiber-tipped pen (in contrast to the marker, which generally has a thicker point) by Yukio Horie of the Tokyo Stationery Company (which later became Pentel).

The marker reservoir, which holds the ink, is formed from polyester. The "felt" used for the tip is usually made of highly compressed synthetic fibers or porous ceramics. Toluol and xylol were used as solvents for the dye and are still used for the indelible ink in permanent markers. Due to their toxicity, they have often been replaced with less critical substances such as alkyl or cyclic alkylene carbonates (like propylene carbonate) in other types of markers. Water content of the ink can be up to 10%. Besides solvents, and the dye itself, the ink may contain additives (e.g. nonylphenylpolyglycol ether, alkylpoly-glycol ether, fatty acid polyglycol ester, or fatty alcohol ethoxalates) and preservatives (e.g. 2-Phenylphenol and its sodium salt, 6-acetoxy-2,4-dimethhyl-m-dioxane).

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