What are NPS signs? The signs we make are digital high-pressure laminate signs ( dHPL ) and porcelain fired enamel signs. Both are rated for prolonged outdoor sun exposure and are popular at parks, zoos, airports, civic venues, museums and increasingly as semi-permanent architectural component signage and walls. So how are they different? The dHPL signs are digitally printed and laminated onto multiple layers of a substrate that is made to be vandal-resistant and weather-resistant. Based on the elaborateness of the designs, it's usually less costly to create a dHPL sign. The porcelain enamel signs often last longer but are prohibitively expensive for most short-term signage (signs which are easier to replace) needs or projects when a budget must be adhered to. Signs shown with optional double-post mount frame and special shape cut for permanent outdoor exhibition When the sign location will be in an unsupervised area like a campground, park or is designed for ...