Recycled paper greetings cards reduce waste, and are far better than paper printed with FSC-paper (which still involves trees being chopped down).
Never sent plantable (embedded with seeds) cards to homes with pets, as many have wildflowers which are toxic to pets.
Stephanie Cole Designs offers really nice greetings cards, all made from recycled card and sent in recycled envelopes. When their cellophane protective packaging runs out (recycle at kerbside or supermarket bag bins), cards will all be sent ‘naked’ (without packaging).
One Tree Cards (don’t send plantable cards to homes with pets)