MAGNET technical additive 300 ml MAGNET technical additive 300 ml The MAGNET technical additive 300 ml is a chemical additive used to increase the viscosity of paint or other coating materials. It is designed to be added to a liquid paint or other coating material in order to increase the surface adhesion and overall durability of the coating. This product is designed to be used in conjunction with the MAGNET paint line, but can be used with other coating materials as well.