Here's why:
* Ease of use: Spring clips are easy to attach and detach, making it convenient to change sheets or add new ones.
* Secure hold: They provide a secure hold without damaging the drawing sheet board.
* Versatility: Spring clips can be used on a variety of drawing boards, from small table-top ones to large studio boards.
* Availability: Spring clips are readily available and relatively inexpensive.
Other materials sometimes used for fastening drawing sheets include:
* Pins: Pins are good for temporary attachment and can be used on softer materials like cork boards, but can puncture and damage drawing sheets.
* Tape: Tape can be used to secure drawing sheets, but can be messy and difficult to remove without leaving residue.
* Magnetic strips: Magnetic strips are helpful for holding sheets on magnetic boards, but not as versatile as spring clips.
Overall, spring clips are the most practical and widely used method for fastening drawing sheet board due to their ease of use, secure hold, and versatility.