I started a thread about 4 weeks ago - asking how thick glass shelves should be. After settling on 3/8 inch tempered, I set about building a soltion that would fit inside this existing setup - a 4 foot window set in a wall with two existing 'built-in' book-cases. This is an image of the 'before' situation... a few pieces propped up above sill-line, and a bunch more on a desk surface (not to mention a couple of dozen in various bedroom.