A window system is provided that includes an electro-optic element having a first substantially transparent substrate defining first and second surfaces. The second surface has a first electrically conductive layer and a second substantially transparent substrate defines third and fourth surfaces. The third surface has a second electrically conductive layer and a primary seal disposed between the first and second substrates. The seal and the first and second substrates define a cavity therebetween. An electro-optic medium is disposed in the cavity that is variably transmissive such that the electro-optic element is operable between substantially clear and darkened states. A polymeric dust cover is positioned away from the electro-optic element defining at least two major surfaces and at least one indicia disposed in the dust cover. The indicia includes a plurality of damage channels having an aspect ratio greater than about 10:1.