My laptop stand brings the screen much closer to eye level, but not quite close enough. I want to raise it a few inches by placing something underneath, but I can't think of what to use. The bottom of the stand is a solid flat base 13" by 11".
1) Old books (or, if you have any, old phone books). If they don't cover the entire 11x13 area, combine multiple books, each nearly the same thickness, side-by-side. Duct-tape them together so they don't slide apart.
2) If you happen to have four unused hockey pucks: trim a board to the required 11x13 dimension and place it on to of the pucks, one puck at each corner. For additional height add another puck under each of the original pucks. Secure the stand by drilling a deck screw through the board down into the pucks.
I use plastic foam wedges. Strong and light, they create the space I need under my laptop to keep it from overheating (laptop fans FAIL often after a few weeks). This material comes in sections that can be snapped off to accommodate your height requirement. They have adhesive backing if you want to affix semi-permanently.