Light Large

What can I use to diffuse the light that comes in to a large window?

I have a large bedroom window that is south facing. The room gets too bright and hot from spring onwards. I have tried a blackout blind but that kept the heat in.
I have heard of a film that you can stick on your window to diffuse the light and heat. Does anyone know where I can get this? Or does anyone have any other solutions?

another thing you can use (depending on how big your window is) is Gallery Glass, which can be found at craft stores. It’s a gel that you paint onto the window to make it look like stained glass, they have some that looks frosted. Yes, it would be a giant pain in the butt if you have a large window, but if you wanted something a little more creative than the window film that would be a good choice. When it dries, it’s like plastic and will peel off the window.