The spikes are blunt and flexible. These also look like sea urchin spikes but of course the color is not a match.
The polymer clay comes out like a hard rubber texture after the 15 minute curing in the oven.
Here's another design you might like.
This design is made for a larger wrist measuring 8 5/8" (219 mm) inside circumference.
Sculpey and available in craft stores and online.
The closure is an oversize black plastic button and loop.
design and photographs © copyright 2013 WhatKnotShop
Dinosaur Time Machine"