Why give a paper valentine when you can give a 3D printed one!?
Hand this to you valentine: a 3D printed thick standard business card size. The card reads "Happy Valentine's Day" on the front with small instructions to clip the hanger of the heart to remove the 3D pendant ready to wear (chain not included). The back reads:
ROSES ARE RED
VIOLETS ARE BLUE
HERE IS A PENDANT
3D PRINTED FOR YOU!