Hello,
I just googles "6 inch plastic canvas hearts" and a few websites came up that had them. We get our shapes from the manufacturer, Darice, and I don't think they make these shapes in a 6 inch size? I think QuickShape does though. Annie's Craft Store came up and so did Wal-Mart and JoAnn's so I would check those websites out :) Hope this helps!
~Kristi @ EPC