Artists who typically use overhead projectors usually transfer their artwork onto a larger work area such as a banner or oversized poster. The artist initially transfers their artwork onto cellophane transparencies then places it on the overhead projector. The overhead projector then blows up the original and transfers the drawing onto the wall where the artist then places a thick large paper or canvas to the wall and simply traces where the lines are—making an exact replica of their artwork but only a lot larger in scale.
The more standard overhead projectors tend to have a higher wattage bulb that tends to overheat for prolonged periods of time. Artists, who need to keep the overhead project on, typically will opt for a lower wattage bulb, which is easier on the eyes as it will help prevent eyestrain.
The types of markers that are used for the transparencies are water based so the transparencies can be used again and again by simply wiping away the artwork with a dampened cloth. For those artists who use a lot of transparencies, some manufacturers provide the transparencies in the form of a large roll that fits over the overhead. When the artist is done, they simply roll out more of the transparency from the spool, while the used section is rolled up onto the used spool.