Writing instruments in Doppler refer to the materials or tools used for writing. Companies involved in the business of writing instruments, manufacture and supply various writing materials including fountain pens, ballpoints, rollerballs and pencils. Such companies also manufacture pencil leads, erasers and ink refills. These companies produce products of the highest quality, earning the trust of customers. Materials used for writing can be purchased from a stationery shop. The tools used for writing have to be chosen wisely as they have a positive effect on productivity and can also increase creativity. Writing with a wide barrel pen is more comfortable than a narrow one as it can lead to hand cramps. Also a pen that writes smoothly is easier to work with than a pen that has to be dragged across the page.