Machine question: Presser foot up or down when machine Sewing Machines Parts and Sales in Los Angeles

Hi everyone,

I’ve always heard the common wisdom that you should leave your presser foot down with some fabric under it when your machine is not in use. I’ve heard some people say that it’s not good to keep the spring in the presser foot lifter compressed by leaving it up, but I’ve never seen a definitive source for this common wisdom.

I recently got a Singer 99k sewing machine, and the manual for it said, “Caution: When the machine is not in use, raise the presser foot by means of presser bar lifter to prevent injury to the presser foot and the feed.”

Is there a compelling reason to leave the presser foot either up or down? Is the manual just saying that the presser foot/feed dogs can be scraped up if you leave them in contact? So could I just put fabric under the presser foot and achieve the same effect, right? What position do you leave your presser foot in when it is not in use and why?