Client is a local heritage society that wants to post signs outside variety of buildings with photo showing what they looked like 100 years ago. She wants cheap and durable. She didn't say fast or I would have reminded her she just gets 2 out of 3. With 40 to 60 different images, I'm thinking my best option is the 4 ml or 10 ml coroplast gang run like signs365 does. But many buildings won't have option for step stakes in grass. Client referenced another community with a similar project that stuck signs in buckets of sand set on sidewalks outside buildings. Any other thoughts? Not sure a window option works because might not get as much attention and availability in each building will probably vary. 10 ml have any more durability than 4 ml if I go that route?