I'm a cartoonist and would like to create professional level art on my ipad. I've purchased ArtStudio but have found that the dpi level is preset to 72. Are there any drawing apps that allow the user to manipulate the dpi or increase the image size up to 20" (one of my clients has that requirement). I love drawing with it, but I'm concerned I can't format the way my clients will need. Any insight would be helpful.