Calibration of the Tablet stand is performed using fixed grid markers. The following 5 point calibration grids vary in size for various screen sizes. Choose the link best tracked for the size of display being recording.
Alternative calibration grids (min 4 points, max 9 points) can be created as locally hosted webpages, a static image, PowerPoint slide, or even just printed out and use on paper. Each calibration point is labeled (10.png, 20.png, 30.png, 50.png, 60.png, 70.png, 80.png, or 90.png) which correspond to calibration points 1, 2, 3, 4, 5, 6, 7, 8, and 9.