Notice that there are two versions or flavors of gif file formats: GIF 87a and GIF89a. The later is a new file format that has been developed to handle transparent gifs ... a gif image in which the background is transparent and thus allows the Netscape background to "show through" the image. Let's look at two versions of the same file:
|GIF 87a format||GIF 89a format|
The picture on the right has been given a white background and then saved in the gif89a format. Chuck Musciano's transparent gif tutorial shows us the steps for using LviewPro to create a transparent gif image.
The Transparent/Interlaced GIF Resource Page is a good gude to other resources.