Seals stones often have decorative knobs carved into the top of the stone but these can get in the way when carving a seal. Working artists and scholars often prefer a plain stone—one with a flat top that makes it easier to press your palm against the inked stone down onto the paper. But a seal carver can’t avoid now and then using a stone with a decorative knob. If you hold the stone in your hand while you carve, with the stone upside down, the knob will be at the bottom. This makes it hard to avoid bumping or scraping it against the table top—with the potential for damage. One way to avoid this problem is to use a seal vice. Just be sure to provide clearance between the stone and the bottom of the vice so the stone doesn’t touch the table surface. For an expensive stone it might also be a good idea to lightly wrap the stone before putting it in the vice. Even though most seal vices have jaws made of wood they might still scratch or leave bruises on a soft stone. It’s stressful enough to design and cut a good seal impression on a valuable stone someone has entrusted to your care without worrying about the carving on the top of the stone too.
The image of the seal illustrated above is culled from the internet.