Round 11mm is about 7/16" flat back acrylic (plastic) cabochons. Absolutely perfect for decorations of all kinds. For garments and crafts. Lead Free acrylic (plastic) safe for skin and can be used as face jewels. Add dimension and sparkle to your projects with these fine quality acrylic gems. Easy to use, fun to do. Smooth with a flat back. CPSIA and RoHS compliant. Professional Grade. Perfect for jewelry making, fabric embellishments. Perfect for jewelry making and garments embelishments Costume making, cosplays. Also used for cards annd invitations, face painting and body art. Domestic made high quality gemstones are also highly suited for apparel and accessories manufacturing. Since they lead free they are 100% safe for skin and can be used as body gems.