I have no idea what I did wrong.  Or even if I did anything wrong.  After clicking "print label" and choosing printable postage with DC,  I entered the weight of the paperback as 7 oz., anticipating to pay for and use the Media Mail rate.  Then I adjusted the mailing date for tomorrow's date and printed the wrapper.  A little later, when I started wrapping the book, I then noticed the postage was for FIRST CLASS mail, not MEDIA MAIL.   Before I taped it, the book weighed 6.9 oz. and even though I skimped on the mailing tape, the book now weighs 7 oz..

What can I do?

I posted this same question in Questions About PBS forum with no replies so far.  This is probably the appropriate place for my question.

It's ok, Jan! First class rates would apply to your parcel up to 7.0 oz., and since it's First Class, it will get to it's destination quicker that media mail!

Oh, thank you, Connie.  I am so relieved.  It was the "up to 7 oz." that worried me.  However, I've got to hope that during this busy time of year that my mail carrier who will pick up the book tomorrow will not heft it up and down in his hand and say:  Oh, I do believe this might be one-tenth of an ounce over the limit. " LOL  I really DO like being able to mail my books from home!

I appreciate your response to this post and appreciate ALL the responses you make in this forum. 

Jan

If the First Class rate for a book is only a few cents more than Media mail it will choose first class. I've mailed many a book with PBS postage where the first rate cost was only $2.15 as opposed to the MM min cost of $2.13.  If 1st class is cheaper it will automatically choose first class.  So make sure you adjust the wait if you are adding an extra book or use heavy packaging.

Bumping this as I had the same thing happen to me.  The initial "print" page says media mail, but the actual label printed out 1st class.  I know my package will end up being more than 7 ozs (didn't bother changing the weight on the front page since it indicated media mail).  Can I cross out the First class box and write in Media Mail?  Or should I just slap a couple of stamps on it?

Kristen, just cross out First Class and write Media Mail.  I've done that before with no problems