Multi-layer toning....? I've not heard of that term, it sounds more like something one would do in PS or some such processing program. I've done split toning, usually with sepia, where you dilute the bleach and pull the print before the blacks have been bleached out. You end up with only the lighter values getting bleached, and subsequently, sepia toned but with strong blacks left in the image. um, there is also dual toning, toning first in one toner, rinsing/washing, then toning in another. The effects can be really cool. What is multi-layer toning?