A method and apparatus for treating the surface of an insulating strip for use in the manufacture of multi-pane windows. The apparatus and methods of one embodiment of the invention includes a texturing roller which leaves a textured impression in a surface of the insulating strip, thereby improving the desiccating and altering the sheen and otherwise affecting the appearance of the insulating strip. According to an alternative embodiment of the invention, method and apparatus are provided for laminating a moisture vapor permeable layer onto a surface of the insulating strip. The apparatus of the invention also includes forming rollers for restoring the profile of the insulating strip.