Choose a page layout and image sizes. Note the print preview in the right pane.
Towards the bottom of the panel, you can choose the number of prints per picture.
The option Crop Images Automatically will proportionally scale images to the chosen width and height. If necessary, either the long or the high sides of the pictures are cropped to exactly fit the chosen format.
If the option is de-selected, then StudioLine underfills the images the images will be printed uncropped but one side may be smaller than the chosen format.