TREND Stinky Stickers Variety Pack, Colorful Favorites, 300/Pack Why simply stimulate the eyes when you can create fun smells as well? Round, scratch-and-sniff stickers are a great way to help motivate students and celebrate achievements. All stickers are acid-free and safe for use on photos. Illustration: Colorful Favorites; Color(s): Assorted. Safe to use on photos.TREND