Your baby will continue to be fascinated with high-contrast images until they're about 14 weeks old.
Notice how they may stare at the black and white cards for minutes at a time. If they've seen a particular card many times, they might not look as long. Your baby is craving more variety and complexity as the connections between their brain and eyes strengthen.
Here is a downloadable link to more high-contrast images for your card holders. You can also tape them up near your baby’s diaper-changing station or attach them to the sides of The Play Gym. Notice all the black and white that is already around you: a black and white shirt, a high-contrast patterned pillow or blanket, or black picture frames against a white wall.