Originally Posted by ckcowl
your top and backing should be nicely pressed-wrinkle free before sandwiching.
If it was nice and wrinkle free before sandwiching - it should be okay now - even if it does look a bit rumpled after unfolding it after storing it for a while
But if it was wrinkled before assembling it - you will save yourself (or your quilter) a lot of aggravation later if you take it apart and press it now.