Radnor Solvent Removable Penetrant is used to examine the surface of an item (non destructively) for surface-breaking flaws, such as cracks. The penetrant is applied to the surface and left to soak. The liquid is drawn into any cracks via capillary action. The liquid is a red dye. After the soak time has expired, the excess penetrant is wiped from off and a developer is applied. The developer is a dry white powder suspension that is spayed on the component. The developer is drawn out of the crack by reverse capillary action, resulting in a colored indication on the surface that is broader than the actual flaw, and therefore, much more visible. This technique can be used to detect surface flaws on essentially any non-porous material.