Reflective Signs Are Hard to Ignore Easy to spot by day, and reflective at night, use these No Parking Any Time signs to protect your property and make sure no one parks in an unauthorized space. 3M Engineer Grade [“EG”] Reflective 3M Engineer Grade reflective signs are the most common material found on our public roads. 3M Engineer Grade signs have 7 year outdoor warranty. USA's Oldest Sign Manufacturer Family owned since 1918, we take immense pride in our signage. Being one of the oldest certainly means we know this business in and out. Our South Dakota factory is the oldest manufacturer of metal signs in the USA. We have been an integral part of safety and convenience our signs have provided over the years. Industry Leading Durability 3M Engineer Grade signs have a 7 year outdoor warranty, but most signs last much longer. Our signs are laminated for enhanced performance. You can clean off graffiti and your graphics are protected. Unlike many other signs, our No Parking Any Time signs use industry-leading 3M inks and not off-brand or other low-durability ink jet pigments that fade in a year or two.