After using these my first thought was "Where has Mulberry Silk been all my life?" These pillow cases are great and I wouldn't swap them out for any other kind. Not only were they cool all through the night, but they are extremely soft. My cotton pillow cases are hot against the face and I'm always turning the pillow and wake up with a damp head. These were like heaven, and now I can really enjoy the full comfort of my expensive pillows. Will only buy these from now on for sure.Also, I don't know how they did it, but they have a very appealing Metallic shine to them.