A web conveyor is provided having a frame, a pair of conveyor rails, and at least one sag rail. The pair of conveyor rails is carried by the frame in laterally spaced-apart relation. The pair of conveyor rails is configured to support and convey respective edges of a thermoformable web of plastic material. The at least one sag rail includes a friction-reducing material provided along at least a portion of a top edge of the sag rail. The sag rail is provided between the conveyor rails and extends longitudinally along a web travel path. The sag rail is configured to support a web of material intermediate the conveyor rails. A web support apparatus having one or more of friction-reducing material, local, raised portions, and a temperature regulator is also provided.