"Please Keep Off the Grass" Sign by SmartSign | 7" x 10" Aluminum DURABLE ALUMINUM. Signs are made from heavy-duty, 40 mil thick aluminum. Unlike steel signs, our aluminum signs do not rust. Signs last over 7 years outside. LAMINATED. To achieve maximum durability, sign graphics are protected with a laminate. This provides enhanced weather and graffiti resistance. ROUNDED CORNERS. Signs have rounded corners and burr-free corners for safe handling, longer life and a professional appearance. EASY TO INSTALL. Signs have four 3/16" od corner holes. Mount with screws, nails, tie-wraps or wires. Signs can also be attached with foam or double-sided velcro tape. Sign attachment accessories are not included.