Using this water doodle book is easy. First, fill the water pen with water. Then, simply draw or color within the lines on the pages. You'll see the dino world scenes pop up right away. As the water dries, the pictures disappear, and you can start all over again. Keep in mind that only use clean water in the pen to avoid clogging. Also, don't leave the pen uncapped for too long as the water might evaporate. When you're done using the book, store it in a dry place. That way, it will last you a long time and provide endless fun for your kids.