The maximum print size on a 3800/3880 is 17" x 37.5" using the Epson driver. If you use a RIP there should be no limit on the length. When printing longer than 37.5" you may run into issues with paper alignment resulting in skew errors. I have printed sheets that are 13" x 40" to print panos that are 12" x 37.5". They printed perfectly.