Hi folks. I have been playing with Gravit for a few months now and things are going well. The latest thing I would like to do is create an image that can be printed in different sizes. To do this, I need a specific aspect ratio. For example, I would like to create a jpg that is printable in 8"x10", 16"x20" or 24"x30" (whatever my customer chooses.) For this, I need to set a 4:5 aspect ratio. How do I set this? Thanks!