OpenOffice.org Impress: Using Master Slides Aug 26, 2008, 19 :31 UTC (0 Talkback[s]) (2755 reads) (Other stories by Bruce Byfield)
"It's all a matter of contrast, really -- which is why a background of a full-color photo is usually a poor choice for readability. No matter what text color you choose, some part of a background photo won't contrast with it. And, given that the perversity of the universe is set on stun in such cases, the text that blends into the background will probably be the text you want to emphasize the most. If you must use a photo, try to position it on the edges of the slide or in a footer (see below), where it is less likely to conflict with text."
