The Excimer lamp diffuses a single wavelength of 172 nm of very high energy which polymerizes a very thin layer on the surface of the varnish. This difference in state between the polymerized surface and the depth of the still wet film causes a stress that develops folds on the surface.
It is these micro wrinkles that provide the deep matte properties by effectively diffracting the light. The film is then cross-linked in its totality with a UV lamp in order to give it the final mechanical and chemical performance. The principle is very different and more efficient than a traditional UV varnish with a surface relief brought by silica grains contained in the wet film.