These hats were donated to Alberta Children's Hospital April 17, 2015.
Not everything crochet has to be wearable.
These 3 are made from 100% wool, intended to be made into aran sweater back when they were in fashion. To keep the fabric firm they are crochet with 2 strands held together, with 8mm hook. They fit together reasonably well just as made, but I then blocked them by fitting each over an appropriately sized container, and spritzed each just to damp. Once dry they nest together perfectly.
Actually this wool has been here before. Another instance of the benefits of ripping out.