Stamping and Stitching blog and still love them.
I'm using one of the Thank You stamps from the Thanks set from Quietfire Design
... and if you want to see more details and descriptions, just click on card image and enjoy
And it fits for these challenges:
TSG Clear Stamps #136 Thanks or gratitude
City Crafter #88 mainly white
Creative Craft Challenge White on White
Crafty Creations #149 Thank You