"Stop - No Thru Traffic, Private Drive" Sign By SmartSign | 18" x 18" Aluminum DURABLE ALUMINUM. Signs are made using heavy gauge, 80 mil thick aluminum and do not bend easily. They outlast plastic signs, which can be easily torn off. Signs last 10 years outside. LAMINATED. Graphics are protected from weather and abuse. Graffiti can be cleaned off. Laminated signs outlast competitive unlaminated or overcoated signs. ROUNDED CORNERS. Signs have rounded corners and burr-free corners for safe handling, longer life and a professional appearance. EASY TO INSTALL. Signs have pre-punched and pre-cleared mounting holes for easy installation. Signs mount to U-channel posts, square or round galvanized posts, wooden posts and chain link fences. STOP SIGN SHAPE. Stop. Read this warning. The octagon shape gets attention and reinforces the importance of reading this sign's headline message.