In some cases, you may want to change the aspect ratio of your Paper Tablet. The aspect ratio determines the active area of a Tablet Page. By default, the aspect ratio of any Tablet Page is 16:10.
The best way to know if the aspect ratio is correct is to experiment with your Tablet Page on your monitor. Draw a pre-defined shape using a drawing tool such as Microsoft Paint and see if it looks correct. For example, draw a square and see if it looks like a square. If it does, the aspect ratio is fine. If it looks like a rectangle, you should try a different aspect ratio.