I have come up with 2 surefire ways to prevent Holofoil "smiling"
1. First off get a binder page iwht the 9 pockets for cards. Put 6
other pokemon cards in the pocket then put in the holofoil. this
creates a wall where the holofoil stands upright on and has no
opprotunity to bend on. ALWAYS KEEP IT IN THERE
2. Get a hard card case and a soft deck protector. Put i pokemon card
in the soft one then put in the holofoil. then add the packet of 2
cards into the hard case so its completely flat. Then put somethiung
heavy on it for 2-12 hours. It wiill be straight, then do step 1 to
ensure straightness.

Thanks for ur time and i hope this helps
Jeff Okrasinski
Omegamm1515@yahoo.com