Working with Layers

Many full-feature image editors, such as Paint Shop Pro 8 or Adobe Photoshop 7, for instance, allow you to add layers to an image. This can allow you to isolate an image's background, for example, from any overlaying text or other objects. This can be very handy when creating transparent GIFs that also include drop shadows or other effects that blend into the background, since all you have to do is change the background layer's color in the original you've saved, rather than having to rebuild the whole image from scratch.