In the following two examples, we can see what happens when we use a "white"
(<td bgcolor="#ffffff" ... >) in the cells containing the
pictures and captions.
The upper pair of pictures have five pixel wide, black borders The cell background
color is not specified, thus the page background shows through and can interfere
with readability of the captions.
The lower pair of pictures is presented with no borders, giving a cleaner appearance.
The cells have a white background giving much better readability of the captions.
In this case the white background blends in with the background picture. When using
other pictures, select a "cell background" color that blends in with the background