How to Make Windows Opaque
If you desire to cover only a portion of the window, cover the area you would like to keep untouched with clear adhesive vinyl. Use a squeegee to push out air bubbles that may get trapped between the glass and the vinyl before proceeding. To add a design element to your painted window, tape a stencil to the outside of the window and use it as a guide while you apply your glass paint. You may also outline your design with black glass paint to create the appearance of stained glass. Glass paint products are available in craft stores.
