SCREENS
There are several different surfaces : beaded, silver, and matt white; each has particular advantages but none has an overall advantage over all the others.
For arrow angle viewing (ie near the projector if this is in the centre of the room) perlux and lenticulated surfaces are better than matt white, but at wider angles the brilliance fall off less rapidly with matt screens and with other surfaces the projectionist may not be aware of this loss of brilliance, Perlux and also present