Summarize this article in one sentence.
. Make sure your resume also comes with a cover letter briefly introducing yourself and the position you are applying for. A cover letter is a basic professional courtesy, reminds the hiring manager who you are, and can highlight specific strengths in your resume that would be of interest. You don't want a resume to show up unannounced and with no instructions. Otherwise the hiring manager won't know what to do with it, especially if you've never met before. Once your resume goes in the envelope, you'll want it to stay flat for as long as possible. You can purchase cardboard envelopes, which are thicker and don't bend as easily, or you can use a piece of thin cardboard in the envelope. You can also add "Do Not Bend" to your envelope as a reminder to the post office. The US Postal Service requires that those words appear above the addressee's name and below the postage. If you add "Do Not Bend," you must also include a stiffener (like cardboard) in the envelope. If your envelope weighs more than one ounce (and with the cardboard, it probably does), you'll need additional postage. Putting a single stamp, as with a letter, will not do the trick. Your best bet is to go to the post office and pay directly there, as they will be able to weigh your envelope to determine the correct amount.

Summary:
Include a cover letter Keep the envelope flat. Add proper postage.