This is how I make striped, translucent polymer clay beads that are clear with no cracks or plaques.  If you hold them up to the light and rotate them, you can see the blue spiral even better.

It’s important to track your oven temperature because heat spikes can prevent this method from working. Below is my baking schedule. The blue line tracks the first baking. The orange line tracks the second baking.

Here are the steps:

 1. I use translucent Pardo Art Clay plus a very thin sheet of it mixed with ultramarine blue pigment.  I carefully condition the clay by rolling it very thin until all white specks are gone and then layer it so there are no air pockets.  I cut off all ragged edges. 

2. Cut the rectangle in half. 

3. Press the corners and ends to create rounded forms.  

4. Twist and form the beads.  As a final step, roll them briefly with an acrylic block. 

5. Put them on a bed of cornstarch inside an aluminum baking box in a cold oven and bake them for one hour at approximately 185˚F.  Let them cool in the oven.  I think this step is key to avoiding plaques and cracks because it allows gases to escape before the outside of the bead becomes hard and traps them inside.

6. Remove them from the oven, put them on a small tile on top of a Teflon sheet, cover them with a tent of aluminum foil and bake them again for 35 minutes at 290˚F starting with a cold oven.  When done, prop the oven door open a little and let them cool in the oven.

7.  Sand and buff them.

They’d probably be even clearer if the second baking was longer or hotter, but I’m happy with the result and don’t like the yellowing that might create.