White type on black backgroung
Tips and Tricks
At the risk of starting an argument all over again, black versus white background, there is a well documented perceptual effect called the "surround effect". The image/photo appears different depending on the surround, light or dark. In principle, you can set the image tone reproduction (brightness/contrast) for either background. It will be optimum for only one. You can readily see the changes if you change the viewing condition on your computer screen. This is one of the reasons that slide film, to be viewed in a dark surround, has different tone reproduction characteristics than, say, negative-print. In some digital cameras there are such setting, but they are not labeled as such. A light surround makes the image more contrasty and a dark surround lowers the apparent contrast.
I plead ignorance regarding graphic design question.
BTW historically it was not so easy to print a good uniform black, so it was often discouraged as a design option. Technology limitations often dictate design decisions, and the reasons for the decisions are not always stated.