Cards and methods of securing hidden symbols on cards are disclosed. The cards, such as instant-win lottery tickets, utilize continuous overprint inks that mask the boundaries between their "secure" and "unsecure" portions to inhibit unscrupulous players from successfully tampering with them. By reformulating the overprint inks to permit a single set to be applied to both portions of a card, more vibrant and aesthetically-pleasing graphics may be displayed as well while utilizing fewer printing stations during the printing process.Alternatively or additionally, the cards may be embossed for added security. Raising portions of the secure area of a card above the remainder of its surface produces irregular features, thereby inhibiting both improper removal of the upper latex or other coating and photo reproduction of the card. The varying card height caused by embossing further inhibits heat-based tampering, as heat transfer to the irregular surface is no longer uniform.