In our collage designer, you can set the print format of your collage using the “Size” button on the right.
We recommend that you always set up your desired print format first, before you start designing the collage with layout and images. That way the image file created for printing, is exactly in the aspect ratio you want your print to be in.
Also please keep in mind, if you do want to change the print format during the design process, make sure that you keep the same aspect ratio as the initial format, to ensure that the entire image is printed. Of course if you ultimately decide on a totally different format and aspect ratio, that is possible too. Just pay attention to how that may effect the visibility of all parts of the images.
We stronlgy recommend using the preview function in the product designer to get an impression of how your print will look, before you complete the order.
If you need advice during the design process, please contact our customer service team directly at service@myposter.com