The text in your resume should be relaxed, not cluttered. To achieve this, choose a font size between 11 and 12. Most job seekers keep their font small since it lets them pack more information into a singe page. But instead of accomplishing that with small fonts, use more efficient word choices to clear up more space. Selecting tight, specific verbs. Get rid of adverbs and adjective. And remove any negative or irrelevant information that doesn't directly help your core argument (e.g. why you should get the job).