I've had no fogging issues and have been using ALOT of polygrade for the last few months. But maybe I got lucky with my batches..(?). At any rate - I can't tell you about lith/toning response- but I can tell you all about toning with it. It's very sensitive to toning - and will yield very strong color changes with most toners. Selenium toning tends toward the red, if anything - and you have to be careful to pull early - not to take it too far. Most sepia type toners will give you a very vigorous response - again- exercise prudence not to get too 'cartoony' an effect. I've been playing with it with various sepia, titanium, and bleach/split toning processes (selenium and thiourea dioxide).