Used these on a recent trip.  My clothes were organized and not wrinkled.  I ended up taking more clothes than I needed because the packing was more compressed.  Envelopes are well made and easy to use.  I have just ordered the 18" size to use for pants and larger items like sweaters.  I used the 15" size for tops and dresses.  (I am a size 10 and wear medium or large tops.) Men would need the larger sizes.