I enjoyed the actual quality of the mylar itself. They are easy to staple and sturdy... However, Mylars are wrapped in a thick rubber band that leave gray marks on the top mylar in almost every bundle. There were multiple mis-cut mylars, some were stuck together... While I did get credit for these, It was not worth my time to go through each and every mylar to pull the defected mylars out, especially since extras were not given in the bundle to account for them. Transline carries the Cowen mylars. Do you self a favor and spend the extra .20 to .25 cent and purchase the Cowens... I started using them about 2 months ago and i love them.