Here the wing halves are in the bag and I am making sure everything is ok as the vacuum bag sucks all the air out. On top of the glass on the wing panels is "peel ply" which is used to soak up resin. Some paper towels are on top in case the there is too much extra resin and needs soaking up. When the wing is dry in 24hrs, the peel ply is removed and it takes with it excess resin that it soaked up, thus reducing weight.