I'm a US citizen living in Canada, I am currently filing my back taxes for the year 2015, 2016. I completed both on turbo tax software and printed to file by mail as required by the software since the e filing period for the above mentioned years has expired.  I printed the return forms and realized that there is no area or block on the forms for signature.  I'm a little concerned about that , my question is:  Am I supposed to sign my return printed form when filing by mail? if so , where.

Thank you for your help