There are many benefits to writing on a vertical surface. Vertical surfaces can make an average writing activity into a great activity for developing fine and gross motor skills. Using vertical surfaces strengthens shoulder and arm muscles, as your child’s arm must move against the pull of gravity in this position as she/he lifts their arms to reach. Vertical surfaces also places your child’s hand in the best position to develop wrist strength and stability. You can buy window markers in any craft store and they wash off easily with a little windex….get writing and have fun!