I found it! The perfect casual stationery I've been searching for forever! OK, maybe I'm being a bit dramatic, but seriously, I've been looking everywhere for stationery I can use to send a note or a thank you or a simple hi! I was looking for a compatible color, size and style. And I found it with Crane's Kate Spade idiom notecard set.
It's super simple - just a card and a matching envelope. But the details and finishes are outstanding! The cards come in 4 colors with a coordinating envelope. Each card/color has a special idiom: "the grass is always greener" for the green card, "in the pink" for pink, "out of the blue" for blue and "red letter day" for red. Adorable.