One other thing about Screen Goo, if you take that route. You would only use one of their gray formulas if their online website recommends that for your projector. They have many variations depending on the projector your using. They have spent many years developing the various formulas.

So, read their website, check to see what they recommend for the projector your using, don't just go with gray because some wacko guy told you to.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85