Yep, Linda's explanation is one way to do it. The other way is to ink up a stamp with a light colour and then "kiss" it with another stamp inked in a darker colour. Your first stamp needs to be quite solid and your kissing stamp is best if it's one with a small pattern or something that fits into part of your solid shape (for example, a swirl kissed over part of a silhouette bird image).
HTH!
|