Just thought I'd pass along this little tip. I read about this somewhere several years ago, but I'm just now getting around to trying it. I've used several things for modeling window shades before: construction paper, bits of styrene, & those little paper "curtains" that come with some kits. Last night, I decided to try something different - used coffee filters. Get the used filter out of the machine, wash it off, & hang it up to dry. Cut them to the size you need, use a dab of white glue to stick them to the back of the window glazing, & voila! - old, dirty shades! Just thought I'd pass that along. Have a great day, everybody!