ImpressArt Uppercase Stamp Set, 3mm, Ballroom Boogie Size: 3mm. New oil-free coating to protect against rust. Each stamp labeled on side for easy identification and orientation. Letter sets include full alphabet and 6 bonus punctuation and design stamps Will stamp soft metals including gold, silver, copper, brass, soft steel, aluminum and also wood Stamps are made of carbon tool steel, hardened to last project after project. Stamp set comes in individual plastic case.