Why not have a stash of gender neutral peacock feather flat birthday cards sitting around your house for when the moment strikes you? They're pretty...printed on luxe white paper that is nicely textured and partly cotton. They measure about 3.5 x 5 inches and are perfect for a birthday note; not a birthday novel....
You get 8 cards and envelopes, printed with my epson printer.
Two color choices:
ochre feathers with khaki envelopes
teal feathers with beet envelopes