Not Complete Without It
Any complete digital video film should have text in it at some point in time. Whether it is employed in just the title and credits or it is used creatively throughout, the film will not present itself as complete until it uses text slates as a qualifier. Though it is often easy to add them in post-production there are some things to keep in mind so the text is useful and not distracting.
One key practice is to always focus on making the text legible at all times. There are a variety of tools within non-linear editing software, as well as other digital video editing programs, that can create amazing animated text boxes. These can be great, but it ends up being too overwhelmed with visuals and movement and can distract from its original purpose. Try to find a font and style that will be expressive toward the motifs in the film, but also will be easy enough to read.
No Blending Colors
The color and style of the text must also not blend in with the background. White text tends to be the standard in film, especially documentary, production. If you are using a text box over a very brightly colored object or background then you should avoid white, which will be difficult to make out.
You also need to make sure that the text is large enough for the audience to read. There is not a set font size that should be employed, but it should be legible from up to fifteen feet away. This way the text will dominate the screen when it comes on, forcing the audience to read it.
Keep It On
The text also needs to be on the screen long enough for even the slowest readers in the audience to absorb. The standard time for keeping the text on the screen during the middle of a film, as with text that is used to indicate a person or place, is about four to six seconds. You may want to keep text on longer depending on the effect you hope to obtain from the viewer.
Don’t Lose Them
No matter what choices you make you have to keep in mind that anytime the audience has trouble reading the text they have been removed from the flow of the film and are now lost. Focus in on legibility over all else, and make sure that any stylistic choices you make do not overpower the content of the text.