In general, markers are made of plastic and contain an alcohol-based ink. The alcohol-based ink allows the marker’s work to dry quickly, and reduces the chance of the ink spreading where it isn’t intended. Acid-free vintage markers can be useful for special occasions that require years of permanence. Such occasions may include marriages or graduation cards.
The size of a marker says a lot about its intended use. Children tend to use medium tip markers for coloring in coloring books, doodling on paper or for creating visual art at school. Fine tip markers work for civilized practices, such as communicating ideas down on paper or signing checks. Wide tip markers are often referred to as highlighters. The latter is used by students and adults doing research. A highlighter is applied over written or typed text without covering the writing completely. It is intended to catch the eyes’ attention, and to reference important information. The last group of markers is the large tip, or jumbo marker. This size is used for writing on surfaces other than paper, like a cardboard box.
Fiber markers are flexible markers. They work by adding more pressure to make a thick line on paper, or by using light pressure to make a thin line. The fiber tip marker runs ink without interruption and usually doesn’t get clogged during use. It is a reliable writing or drawing marker.
Erasable markers are designed to stick to a surface without being absorbed by the writing surface. Such markers are used for slide projectors and marker boards in classrooms. Erasable markers can be removed from a marker board or projector slide with a cloth. This keeps the writing surface reusable.
Security markers are designed to be seen only by ultraviolet light. When marked stolen items are recovered, the owner of a stolen item can verify his claim to the item with an ultraviolet flashlight.