One of the most difficult steps when I've done cushions in the past was to insert the foam into the finished cover. Very difficult when the foam is expanded!
Cover the cushion encasing top, bottom and all sides, with silk film, with the bottom open. Open the bottom end and insert a vacuum cleaner hose, and turn the vacuum on. The film immediately compresses the cushion.
With the vacuum still on insert the cushion into the cover. Reach inside and add the little strip of dacron along the top edge.
Turn off the vacuum and the cushion quickly expands.
Reach inside and pull out the silk film, being careful not to pull out the dacron strip at top. Discard the used silk film (I've tried salvaging it for re-use, but it's so thin it tears very easily and isn't worth the effort). .
This is the first time I've used silk film and I'm in love with this method, here's a video.
Inserting foam using silk film
