Hello, I'm actually design a font for subtitles, and I'm searching information about it to make the proper decitions, so I'm searching information about dynamic environments and witch characteristics needs a font to work weel in those media.

Any suggestions?

Very broad request.

As a possible start, here are three links, perhaps a bit dated, about close captioning typefaces:

• Cinecav;
• Screenfont;
• Joe Clark’s notes.