For best results make sure to set up your printer so that the image is scaled to fit paper size. Unfortunately this setting is located in different locations depending on the printer you own or the software you use so we cannot be more specific.
Unless otherwise stated, our activities are meant by default to be printed on US Letter size paper *, therefore if you are printing on any other size you will need to take that into account. Usually setting the printer to scale to fit paper size will let the computer figure out whether to enlarge or shrink the images according to need.
* US Letter size = 8.5″ x 11″ = 215.9 mm x 279.4 mm