When I was a kid, I used to like drawing patterns on graph paper. One of my favorite was to draw strait lines from [0,(n-i+1)] to [i,0] for i = 1 to n. When n is large enough (~10), the pattern produces an outer surface that looks curved. Place one at each corner of a square produces the attached designs.

I translated the design into 3d. Attached files (n = 10) include two different thicknesses (the thick stands nicely by itself) and and two different sizes with a loop on the corner for mounting on a wall or as a pendant.

Sliced in Makerware with 0.2 mm layer height and 0% infill. Printed on a Replicator 2 in PLA.