On the boards, the staff is approximately 3.25" high (with about 0.75" between each line of the staff). There is about 0.88" between the top of the board and the top of the staff, and about 1.75" of blank space between the staff and the line of piano keys. The line of piano keys is about 4.38" high, with the white keys each 0.88" wide and the black keys each 0.5" wide. There is about 0.63" of blank space at the bottom of the board. Since the markers are alcohol based it means that every time the cap is off it will speed the drying process. So the markers need to be re-capped when not in use, even if it's only for a short time. Any brand of dry-erase marker can be used when the original markers run out. **The manufacturer recommends that teachers should plan to go through 2 to 3 markers per student per year.** To clean the marker board: DO NOT use a cleaning product - it will make the surface of the board deteriorate. The company recommends using a non-acetone fingernail polish remover, or mineral spirits. DO NOT wash the erasers - use the crevice or edge attachment on a vacuum cleaner to vacuum off the crumbs.