I don't have any patterns or instructions, but an aunt of mine just re-covered an outdoor umbrella un "Sunbrella" brand fabric, and she loves it - says that even in the Hawaiian sun it keeps its colors and integrity. Hope this helps!
Thanks, Libbie. Someone suggested that I use the reflective survival blankets indoors instead. That's also an interesting idea. I wonder what I could put on the reverse sides of them. Not sure.