Pink foam board from Home Depot, cut to fit around fireplace. I duck taped it together (underneath as well). Then, I covered it with quilt batting (folded to form layers). Lastly, I got some cheap fabric from hobby lobby and hot glued it underneath.
Adore this awesome idea! Totally going to do it for the eaves storage door in the family room. We can't put any furniture in front of it, so may as well make it functional and fun! Oh! Apostrophe: Nursery Fireplace Turned Magnetic Chalkboard