A simple customizable bracelet. The band has a circular cross section, flattened on the sides to facilitate easy printing. You control the inner (wrist) diameter, the band diameter, and the number of notches.

Less stretchy than my ruffled bracelet because the curved inner and outer surfaces yield no easily-bent straight corners, but still quite flexible.

The output is a solid model intended to be printed with no infill and no top or bottom layers. (Makerware users may find this how-to helpful.)

Gratuitous cat video: https://www.youtube.com/watch?v=0YzrRmXbmnM

Sample bracelet printed in sky blue Colorfabb PHA/PLA with my Printrbot Simple at 195 degrees C. 0.3 mm layer height.

I recommend printing with no raft or brim so that both sides of the bracelet are clean and clear of burrs or extra material. So, make sure your bed is level and you have good adhesion.