This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
The crease in a soft hat can be kept in proper shape with the aid of a paper clip. The clip is slipped over the fold inside of the hat which forms the bottom part of the crease. - Contributed by Jas. M. Kane, Doylestown, Pennsylvania.
Ill: Paper Clip on the Fold, Holding It in the Right Shape for the Outside Crease