Peek inside any nail salon and you’re likely to see at least one or two young girls getting manis and pedis—and there’s many more doing their nails at home. Teen and tween girls are big business for beauty and personal care manufacturers, and according to recent Mintel research, nail products are a “must have” item for this demographic. In fact, 92% of girls between the ages of nine and 17-years-old use some sort of nail product—making it the most popular cosmetic item among teen girls.   “Simi...