Reply To: 30X 40 Home / Forums / Questions & Answers / 30X 40 / Reply To: 30X 40 Ribbet February 23, 2013 at 9:12 am #1020 Hi Hallie, If you start with a collage layout which is square in shape, you can use the proportions slider at 43:57 or 57:43. This will give you an optimally sized collage that will have very little cropping on a 30×40″ poster. Settings