Web imagery increasingly tends toward losslessness. When we make changes to a design or graphic, we want to be able to apply them without damaging the source material. That way, the original is preserved if we ever need to revert back or make other adjustments.
One of the latest capabilities to fall into the hands of web designers is image processing with blending modes. Blending modes allow us to easily create colorization and texturization and apply other special effects without having to crack open an image editor. This saves time by not having to manually reprocess graphics whenever a change is needed, and prevents the headache of having to recall the exact settings of a visual standard that may have been created months earlier. Instead, graphics can be neatly specified, maintained, and manipulated with a few CSS declarations.