Carbon highlights "eaten out"
I'm still on my Carbon learning curve and I'm starting to get some predictable results.
One thing I can't get over, though, is that all my highlights (zone VIII and IX approx.) look like "eaten out", i.e. beyond zone VIII the gelatin/pigmant is completely gone.
Highlights look like large white holes. The other gradations are perfectly smooth.
I'm using the pre-fabricated tissue from B&S, spirit sensitized with 2%-4% potassium dichromate (12ml for an 8x11 sheet). As a support, I'm using Fabriano Artistico paper with an 8% gelatin sizing (20ml with 4 drops of formalin for a 11x14" sheet, hotdog-rolled). Never had major detachment issues.
I develop my print by turning it face down after de-mating and let it float without moving in 95-105F (35-40C) for 15-20 minutes.
What could I be doing wrong?