I got my PET CRYSTAL sample from China over the weekend and will have a chance to try it out over the week. They advise here are 3 types that are ALR - PET CRYSTAL, PET GRID and FRESNEL. Below is what I was sent by the manufacturer about each.
"PET Crystal: is the main fabric for ultra short throw anti light market. Its theory is sawtooh structure anti-light. Its advantage is ideal anti-light effect and extra improvement on contrast(10 times than matt white contrast). No white fog effect like common fabric, soft light wont let eyes getting tired even a long time movie seeing. It is very good for child's eyes as well.
The PET Crystal from XY Screen is highest quality A Class screen. The other similar one is Fresnel Screen. Fresnel optical screen is easy to be found among famous luxury brand screen. It has perfect front side viewing effect. But side view has a fast brightness reduction, so view angel is not so wide. It is also only for ultra short throw projector. Since its cost is very expensive, only rich man might consider it. For UST anti-light market, PET crystal is main solution.
Yes, we have the cheaper one PET Grid, is a cheap solution for UST projector. Its surface has rhombic grids and bring a little anti-light effect. Contrast is improved a little too due to its grey color. Its effect is far from PET Crystal or Fresnel screen, but cheap is advantage."
As an FYI, I have a quote from them which suggests the PET CRYSTAL is available in both hard and soft, so "hard" is not just limited to the FRESNEL type screen. I attach the photos the manufacturer sent of both the soft and hard versions. Note, that I cannot get the hard version as I am space limited to must set the screen up insitu, hence I've little info to give about these.
Lastly, I believe many of us would probably consider the PET CRYSTAL or PET GRID so here's a video from Youtube I saw earlier which shows the difference... https://www.youtube.com/watch?v=iTJnxMvOzIM
. Per the video, the PET GRID is definitely the weaker option in my opinion.
Hope this helps somewhat. I'll let you know how I get on with the screen sample which I'll be comparing against the ELITESCREEN CLR offering!