By default, ImageReady applies the same optimization settings to every Slice.  However, you can optimize each slice individually, mixing file Types, colors, and other Compression  settings.  To optimize Slices  simply select them and use the applicable settings in the Optimize Palette.

 You’ve created a Navigation Bar , complete with Rollovers as well as an HTML file with a Table to keep the layout of your Navigation Bar intact.  Select File/Save to save the Photoshop  version of the file.  Select File/Save Optimized  As to save the HTML and web images of the file.  To keep the images of the Navigation Bar separate from the images for the individual “contact” button change the subfolder directory from “images” to “navimages” under Output Settings in the Save Optimized dialog box.

Open “navbar.html” in a web browser and examine the Navigation Bar  and the code ImageReady generated.  You’ll notice that ImageReady has created a table and uses a transparent GIF file, titled “spacer” to create a perfect layout for your Navigation Bar.