I have 2 images, both with the image size and canvas size set to A4 (210x297mm). I am trying to combine these images, so when put side by side they fill an A3 page in landscape (420x297mm). So far, the only way I can see how to do this is to add each image as a layer to a new A3 background, but whenever I do this, photoshop changes the dimensions of the image! Where am I going wrong?! Please help, someone!