I don’t like recommending out of Evernote but look at “Whitelines” (WL) dig down a bit, you can buy four magnets to mark the edges of the board and get great shots. https://www.officemax.co.nz/Office-Products/Whiteboards- I fact I got good results using WL as my notebook Noticeboards/Whiteboard-Accessories/Whitelines-Whiteboard-Image-Tags-Pack-of-4-2464772