Distraction-free reading bookmark

Just something I needed for myself. I love reading with a note so I can speedread easier without being distracted by other lines/images. This tool functions as a bookmark and a way to read distraction free. Current outer width is 132mm. The window is 118mm wide and 5mm high. I suspect that you can scale it up/down and it would fit most books, but I might make a parametric version in the future if there is demand. Have to figure out how to do that though (first upload! :) Print thickness is 0.8mm by default, but scale for your own needs. Everything between 0.8mm and 2mm is usable as a bookmark while being thick enough. Happy reading!