Many screens by Da-lite and Stewart won't cleanly resolve on off pixel patterns at 1080p. Some will like Snowmat 100 and JKP Affinity.
The pixel edges should be sharp with no bleed. Re 4k, I.it really sorta depends on screen size, don't you think? If you make it really big, your plaster wall can resolve it. Resolution as far as screens go depends on pixel spacing. The higher the pioxel count and the smaller the spacing between the pixels which is dependent on your screen size, the smoother the screen must be. No texture, no coatings. believe what you want. if you are not a really critical viewer, it probably will make no difference to you. At 4K and traditional screen sizes, you will have a great deal of trouble trying to see grid spacing on 8 million plus pixels anyway on a true 4K screen material..