This is probably due to the fact that you don't print that often, so the nozzles on your print head are clogged. You can try this: go to "print", then "preferences". you will find a tab named "maintenance". There, you will see the option "Head cleaning". Click on that option and follow the instructions. Bear in mind that you might have to do it several times and that cleaning the nozzles uses a lot of ink.
Hope that helps!