This is an activity that I did with my kids but I reckon the decorated paper would be great used for paper-crafts, like a card or scrap-booking. And it is such fun to do too.
You need marbles or golf balls and a box with a lid, the box should be about the size of the paper, I use the boxes that photocopy paper comes in - just perfect. You can leave the lid off to watch the balls roll around and direct them where there is no trail - or just put the lid on and make a big noise rattling them round.
Step 1. Place some paper in the bottom of the box, ideally it should fit without too much of a gap around the edges.
Step 2. Drip or dab some paint on the paper for the balls to roll through. Tip in some balls and rock and roll them. The balls will leave a trail of paint where ever they go.
Step 3. Do another one coz they are so much fun.
Another similar way to decorate your paper is to borrow some toy cars from your kids and drive the wheels through the paint to make tracks.
Hope you have fun and think of some cool ways to use the paper.