This certainly doesn't look factory, but we replaced all the crappy mini blinds in our camper with home-made blackout fabric curtains. We just sewed up square panels slightly bigger than each window, put snaps on the 4 corners, and snap them to the wall. Each panel overlaps the window, and is very snug, can't even see light around the edges. We spent maybe $40 for all 7 windows on fabric and snaps, probably 5 hours sewing (because we're definitely not expert sewers). With everything snapped up, the only light comes in from the roof vents...very dark.