DIY Blackout Blinds?

Does anyone have any ideas on how to create a super cheap, super easy way to create some blackout shades for my bedroom without buying expensive custom-sized blackout blinds?

I fact, I already have custom-sized blackout blinds -- except they're roller blinds, and when they're deployed, although their size is exactly the same as my windows (about 70" wide by 20" tall) when they're rolled down, and the sun is shining on them, the light literally blasts through on all sides, rendering them almost useless.

What  I need is a light barrier that makes the room pitch dark even if the sun is blasting directly on the windows. I looked at this site: http://www.blackoutez.com -- but after ordering, and even if they do ship to Canada, it's liable to be prohibitively expensive.

What I need is something cheap, easily mountable, easily unmountable and able to be stowed in a closet every day, then brought out every night for the next day. I thought of using those dollar store poster boards, maybe taped together with duct tape. Black ones would probably do a good job of blocking the light and they're pretty big -- maybe 48" x 36" -- but there is still the problem of how to attach them to the tops of the windows.

So again, here are the criteria:

Cheap, maybe less than $50 all together
Block ALL light completely
Easily mounted, easily unmounted
Able to be stowed quickly and easily
Durable, able to be used every day for months
Able to recite the Gettysburg Address with no cue cards
(Okay, I'm willing to forego the last one!)

Turn your inner geniuses loose!

Thanks in advance

Nickster

Picture of DIY Blackout Blinds?
Toga_Dan2 years ago

tarps with 1 side aluminized are pretty good. posterboard or plywood can simply be placed on th windowsill. these solutions may not be dark enough to develop film, but ive used em when workin night shift n sleepin days.

Sassori (author) 2 years ago

Sorry, somehow the measurements in the post got weird. They're obviously meant to be 52 inches tall by 70 inches (two windows of 35 inches each side by side) wide -- that is the size of the inside frame of the indented box that the windows are set in. Ideally the solution would have to be mounted as close to the actual glass as possible.