<p>My research mentor wrote me a letter of recommendation for working at the lab. However, the letter isn't on letterhead. He said that the department head won't give him any letterhead paper to write on because the recommendation is a personal letter. My mentor did include his own personal info and a signature, however. Is that okay?</p>
<p>Yes. None of my letters will be on letterhead.</p>
<p>If the admissions officers have any reason to doubt the letter, they can simply call or email to confirm.</p>