G3s and G4s usually have a lot of tape residue, and usually I just rub on it with my thumb until it comes off:/ I haven't found a faster or better way, and it's not perfect by any means. My advice would be after you use whatever method you want(mine or maybe someone knows a better one and will post it), get some parchment paper. Store the cards with a piece of parchment paper between them so even if you don't get 100% of the sticky off, the card won't get further damaged.