If you spray baste it may not be a problem- if it has fold creases, not wrinkles. If its wrinkles then it needs to be pressed. But I have sandwiched tops with folds in them. I spray baste in sections and smooth the top as I go. The adhesive holds it flat. Then to be on the safe side I add a few safety pins here and there so there is no stress on the adhesive as I wrestle it around on my DSM.