With so many choices, it can get a little overwhelming. Below we address the most common factors which can aid you in making a decision

Your screen should be geared toward your audience, regardless of whether it's for office, home theater or otherwise. Specifically, your screen should be large enough to allow those in the back of the audience to easily read the subject matter, but not so large as to overwhelm those in the front of the audience
So how big is that? Luckily there are some rules of thumb to follow <learn more>
Formats are expressed as the ratio of width to height and can be represented either as true ratios (e.g. 16:9) or as a single number (e.g. 1.78, which equals 16 divided by 9). On our site
we've chosen the latter method for simplicity. For example, the width of a cinemascope format screen is 2.35 times larger than its height.
The best format to use depends mainly on the projection source and the projected content itself. For example, if you have an HD format projector and watch nothing but HDTV, then the answer is simple. However, if multiple formats will be projected, we suggest purchasing a screen with the format that you will most often use. The reason relates to wasted screen space. <learn more>

This is probably the most perplexing question when purchasing a screen due to the numerous choices available. Each screen surface is described in terms of its gain, contrast and viewing angle but what is the best combination?
The answer simply depends on your projection source/content, audience distribution and lighting scenario. <learn more>
See a complete listing of screen surfaces - Da-Lite - Draper