If I find the time I'll be happy to make a special version to suit your needs. In addition there are several sites on the web where you can download thousands of free background images. You will find some URL's for background collections in my HTML link-section in my link library. GIF89a includes a transparency index that causes the background color of the display to remain unchanged for the color indexed as transparent . If the web browser supports transparency, that color will be replaced by the browser's background color, whatever it may be.
Interlaced images means the image can be progressively displayed.
When an interlaced file is downloaded, it appears with a venetian blind effect. Interlaced images appears first with poor resolution and then improve in resolution until the entire image has arrived, as opposed to arriving linearly from the top row to the bottom row. This is great to get a quick idea of what the entire image will look like while the GIF image is downloading. LView is an easy to use application for creating transparent GIF files and much more. Click here to go to the LView homepage where you can download the shareware version of this really cool graphic editor.