Torque sealant is a varnish that is applied to mechanical fasteners and usually acts as a "visual safety mark" or inspection seal. Torque sealant is available in different colors and in transparent. Most torque sealants currently available on the market are solvent-based but more environmentally friendly variants, for example water-based (VOC-free) torque sealants, have been gaining in importance in recent years as they are much gentler on humans and nature.
Due to the many different fields of application, there are many different terms that can be assigned to the umbrella term "torque sealant". These include: torque seal; torque seal paint; tamper proof sealant; tamper proof indicator paste; torque inspection seal; torque indicator paste; torque stripe; witness mark; marking ink; screw protection varnish.