Here is what we did for Blackout Shades: Get some” black ballistic material” from your local fabric store – they normally sell it by the square yard ( 3ft x 3ft). Buy enough to cover your windows and/ or skylight with one piece (cut from a larger piece) so you don’t have to sew pieces together to make enough-unless you want to use up every last bit of material. I measure the windows this way: on the sides, I add about 2 – 3 inches for each side beyond the window opening; for the vertical length (top to bottom) I add about 8 – 10 inches. Be sure to have enough over-hangs to cover any sun light angles that might come in from the sides. On the sides, I fold over about 1 inch and sew that down to prevent unraveling over time. On the vertical length I do the same thing but I do an extra fold over at the top so that I can put a ¼ or 3/8 inch wooden dowel through the hole I just made on the top. Since most campers have the curtains already attached, I just take the “black out shades” I just made with the rods at the top and put them on top of the camper’s permanent shades by pushing them back far enough so that they don’t fall off. If need be, I will use a clothes pin to close any open areas. As for the skylight, I do the same thing but make the size to fit the outer skylight frame. This might be about 1 – 2 inches and I go to the outside of the frame for measuring. Then I sew some black Velcro (with hooks) or similar product to the black ballistic material. Then I get the sticky back Velcro (felt/loops) in white (to match my frame) and stick that on the frame of the skylight. Use just enough Velcro to hold the blackout shade from falling. Too much Velcro and you may pull the sticky backed Velcro off. Be sure you have the "hooks and loops" matching or it won't work. Then in the morning we just pull them off the window and skylight, roll them up and put them away. Use of the word “Velcro” is not an endorsement, just easier for folks to understand. Hope this helps.