Here in Massachusetts I use 70% shade cloth when the plants are put outdoors. As far as cloth being used in the windows. I have one sunroom window that faces South and this merely has white lace curtains that brake up the rays. No problem growing under these conditions.
I tried Aluminet a couple of years ago thinking it would lower the temperature in the summer. I could find no appreciable difference in the temperature before and after installation so I took it down. Anyone interested in some Aluminet at a very cheap price? (10 x 24- 40% shade)