Are graphics on a white background preferred by picture editors?

Sphere with equations for area and volume

Images with a white background are easier to integrate with text. To that end, I have re-rendered some of my images to give them a clean white look. They jump out of the page and are ideal for textbook use (and web use, too). Traditionally, I have used a black background. Mainly because I started doing electronic graphics for TV and images worked better with a dark background. Textured backgrounds are nice but can be restricting for some uses. For most images, I can alter the background for a modest fee.

Please let me know what you think: white, black, flat colour, or texture!

Here are some of the newest examples:

Rabies virus on white background
Cylinder showing equations on white

Cone showing equations on white