Each coaster has been sanded on all four sides and also has corkboard on the back to prevent scratching furniture. They have also been sealed with 3 coasts clear sealant to make them safe to put your drink cups on. Wanting your favorite personal pictures on them? No problem. Simply send me an email at leahakay@gmail.com or send me a messae on facebook at Adorably Cute Creations by Leaha.com.