Originally Posted by reconlabtech
Be sure to project onto the finished and dried basecoats before you apply the topcoats to see what you have. You may not need any topcoat or just one topcoat layer instead of two.
I learned this the hard way and had to paint a new base coat, which turned out to be all I needed.
This is good advice. I tend to think of this as a weekend project. Friday night you tape off the screen area and prime if necessary. Saturday you apply two coats of the base paint and let it dry. Saturday night you watch a movie or two on just the base coat. If it looks good then it may be worth while to live with it for a bit before doing any more. If you are sure you want to go ahead with a clear coat then Sunday morning you apply your two clear coats. Sunday Evening you watch some more movies.
Don't put up the border until you are sure it's right.
I really like the new Behr UPTRA UPW #4850 over the Flat Latex #1050. You don't need a separate primer, and if you decide to stick with the matte gray finish then it is much more durable and washable. In addition it levels out to a smoother finish and for those painting any kind of flexible substrate it is more flexible. As an exterior paint I would also suspect it is more resistant to UV damage.
The Flat Enamel #1850 has a slightly higher sheen but it is still a matte finish. It is not self priming but for those with no interest in clear coats it has slightly more gain and is meant to be very durable and washable. Of the three it is probably the best one-can choice.
There is one situation where the Flat UPW #1050 really out performs the others. A rough surface. I suspect that given a cement block wall with reasonable grout fillets, you could apply four coats of UPW #1050 and project an image on it and not see the blocks. So for those who need to project onto the basement wall of your local church from time to time keep that in mind. You might just save your church a few bucks some day.