While publishing a progress report on Gil Russel's spoked wheels development (see this post) I happened to notice that Gil has made a most useful development also of wooden miniature clothespins.
I couldn't resist this, and quickly made may own set (the original small clothespins came from IKEA, I believe). What you do in practice is to turn the spring backwards, by removing one part of the clamp, turn it around, and reinsert it. Then reiterate for the other half.
The new clamp is vastly improved by two new slots for the spring, 15 mm in from the new ends (which used to be the back part of the original clothespin). The slots are easily made by any small hand-saw. No new recess for the spring coil is necessary (which is lucky).
The new clamps are much better for clamping card details, since the clamping area is so much larger and flatter.