Custom Blackout EZ Window Cover (vinyl)
[Custom Vinyl]

Super easy to cut and install. Took about 10 minutes a window.
I'm a home remodeler and have researched every option to blackout windows (wife is a nightshift nurse). This the best and least expensive system going.
Blacks the light out 98%. A very small amount of light comes through the velcro, unless you really press the two velcros together. I used the white velcro on my white vinyl window (black velcro on the cover). Maybe black/black is better.
but with the curtains drawn it's 100% pitch black
Easy to remove it when you want light. I put a small square of the velcro on each corner on the inside face of the cover so you can fold the cover back up on itself. That way the bottom half of the window is open to daylight.
Be sure to thoroughly clean the window area before applying the velcro.