We have just opened the bag and poured the resin in. We used about 1200 g of resin to make this part. We could get away using a bit less next time maybe 1000g. Of this amount not all ends up in the finished part as you need a bit extra to chase some air out of the part. There is also some soaked up by the peel ply which gets pulled off the part after its hard. The peel ply leaves a smooth surface and gets rid of bag lines. Bag lines are those folds or wrinkles in the bag from getting it to conform to the shape of the part. There also has to be extra to wet out past the trim edge of the part.