For CSS opacity to work in the browser it must have some placement specified. We used Mozilla recommends that we use float:left; and that worked. Now we are trying position:relative; and that works too, but only to work in Mozilla Firefox. The float:left CSS style works in both Internet Explorer and Mozilla Firefox. Surely the explanation from W3C makes sense but basically this was trial and error, mostly error to get the transparency opacity to apply to text. The opacity code for simply displaying an image is more straightforward.