Beginner's Guide to Adobe Flash/Filters and Blend Modes/Layering Graphics
If you use Photoshop or other image editing applications, you may be familiar with using blend modes, although for many people this remains a somewhat mysterious tool. Blends are rendering tools that analyze the pixel values of overlapping images (the blend image and the underlying base images) to create a rendered image that is a mix of the two. The type of blend applied will determine the formula used to generate the pixel values in the combined image. Blend modes can be applied to Movie Clip and Button symbol instances in the authoring environment using the Blend mode menu in the Properties panel . The blend image will interact with any underlying images that it overlaps - even if they are not on the same layer.