I purchased this product and am extremely disappointed. The cards are not reusable as advertised. I
tried a few and followed the instructions to restore them, but they didn’t return to their original
state. The ink came back much lighter, making the revelations too obvious. While the concept is
interesting, the product is lacking. I’ve contacted Penguin to request a refund and suggest
discontinuing the product. Although they typically respond quickly, I have yet to receive a reply.