What can i use to cover my windows so that its pitch black?

Question

I have a house that's like 100 years old, so i have pieces of wood on my windows and blackout shades are used to cover 100% glass windows.

Answer 1

Use aluminum foil!

Answer 2

At Joanne fabrics(as well as many other stores im sure) they sell this material called black out.  I used it in my bedroom windows when i worked nights.  It blocks 100% of the light and looks much better than foil :P

Answer 3

use a thick blanket! oh my god are you really asking this? :)  

Answer 4

In college we taped up aluminum foil to our windows to provide 24 black out...its pretty cheap and very effective...