I've used them. They are great. The glue did not leave traces behind either like I was afraid of it doing. I even got mine on sale for like $1.99 at HD. They ar a bit of a PITA to raise and lower if they are going to be used on a window everyday like that.

Do they actually make room-darkening ones?
I don't think the regular white ones block a whole lot more light.
Some come with clips to hold them up during the daytime.

A few weeks ago, I decided to price room-darkening cellular shades. Very expensive.
So I tried another option to see if it'd work for me:
I went to Target and bought tension rods and two room-darkening curtain panels (I bought the ones made for kids' rooms, because the length was better--on my bedroom windows, they hang just a bit lower than my windowsill.)
The tension rods fit snuggly inside-mount on the window, so a lot of light is kept out between those curtains and my draperies.

Yes they do make room darkening ones besides the light filtering ones.

They now make them in plastic too besides the original paper ones too.

http://www.redishade.com/store/rs_room_darkening.html

Here is a link that might be useful: RediShades Room Darkening

Do these just stick to the top of the window without any clips?

Yes, they just stick. They hold tight yet peel away easily. See the RediShade link I posted. There may be other brands out there but I can vouch for RediShades.

I still use a RediShade cut down to small size for the tiny window on my front door. It's been there forever. I just tested it and it still peels away without leaving glue behind and re-sticks just fine. They don't yellow in the sunlight either.

Dilly, you are a doll! Someone gave me one when I put my house on the market to cover an ugly, laundry-room window. It was great (she was a college student). Made the window look very cute.

We have moved to a Townhouse with very strange windows which have mini blinds inside the glass. They don't close well and light streams in the bedrooms. I had no idea where to find these paper shades or whether they blocked sun.

I am so very thankful to you for the link. You just saved us a lot of 'sleepless, early mornings!'

Jane

We have had/have them on most our windows for past 3 years....till we can slowly afford treatments. The ones we have removed starting at about 18 months did leave sticky glue on the window. Needed a razor to remove. Seemed to be worse with those windows that get more sun.

amm0810, did you put them directly on the windows, the glass? I can understand that the heat and UV rays might do that in such a situation. I put mine on the wood. That is the way they are to be installed I believe. It looks better that way too.