I created a card using masking. I cut circles out of a piece of thin paper and then used the negative image as a mask while I stamped a damask pattern on the card. Since this is a simple single-layer card, I added some interest by cutting out a large circle and then stamping the full damask image on the inside of the card. When the card is closed it looks like the image inside the large circle has been masked off, too.
Papertrey Ink cardstock and stamps--Damask Designs; Ranger stamping ink; vintage seam binding tape