A glass window sill will add elegance to any interior. It can be made of plain colour glass or glass with graphics. The most popular motifs are wood, marble or stone designs, but there are also many beautiful watery themes like waterfalls or water drops.  There is an option of a thick 10-12mm glass window sill fitted straight into the window recess or a thinner 4-6mm fitted onto the existing wooden/stone window sill.