Selens Linear Polarizing Film A4 7.8x11.8 inch Non-Adhesive Polarized Film Sheets for Physics Education, Photography, Screen, Experimental, 2Pcs

Was the perfect thickness, polarization and size for the lab I was doing. It was also easy to cut into smaller pieces. It’s a great value for the money because I was able to create a lot of smaller film squares from it.

At first, I put them together while the protective film was still on to confirm that they did work, but the result was nothing. I noticed the tabs on the protective film said screenguard, so I thought I got scammed and these were screen polarizers which do not work for polariometers or polariscopes. As a last ditch, I removed the protective film since maybe the plastic is messing with the light and scrambling it again, and alas, it works! It behaves exactly as it should, and while indeed it does not block light perfectly as others mentioned, this is the result to expect from all plastic polarizers and you won't get total blocking unless you spend hundreds on crystal based polarizers or whatever. For the price this is decent, especially because its a large sheet

They're so flimsy and thin that they roll up under their own weight.

Worked great used on lcd tach gauge and its like new now

Very weird: these sheets when rotated 90 degrees to each other should block all light, and sometimes they do. But reverse the order of sheets or turn one front face to back face and they do not block light at any rotation, rather they let greenish light through (at crossed axes) and orangish light through (at parallel axes)!?!. I think the base material has some birefringence or something to partially ruin the polarization. (Yes I removed the protective film. No, they are not circular polarizers.)Also my sheets arrived with some dents.

It was the least expensive and will probably do the job, but not the highest quality. The polarizing effect is adequate at best.

It worked fine and I have enough to do several more lcd displays just what the mc doctor ordered

It's polarizing film, pretty simple. Nothing special in the optical quality, so you're not going to be putting it in front of a camera, but can be used in conjunction with a glass filter to reduce light intensity. Cuts easily, so I could see this useful for making lots of small viewing windows for an educational purpose, but really on the small side for screens or photo/video purposes.