One Way Among Many
Stiff slick paper slides
between thumb and blade to form
a spiral portal.
Here are 2 quick questions for anybody inclined to think they have already paid close attention to the curling phenomenon:
(1) Does the paper curl toward the thumb or the blade?
Confession: I could not remember which way it curled at the time I took the photo. A few later repetitions answered (1) in the same way. It curls toward the blade. Dunno about (2).