I just finished Laura's Triple Irish Chain. The only request Laura had was for feathers and she wanted it special - it's a gift for her parents. I used my arc and made a plastic template. I marked each corner with the template with my marvy marker. I was able to do the feathers, pebbles as well as the frames all in one motion, just one start and one stop. The feather border was measured, marked, and then remeasured and marked, hmmm.
Thanks for looking!