Same negative, Jill Enfield’s sensitizer formula1 and Henry Hall’s sodium acetate developer (cf. Christopher James, The Book of Alternative Photographic Processes, 2nd ed., Delmar, Clifton Park, USA, 2009)
The first photo is on Fabriano artistico HP, the second on Arches aquarelle HP.
Changes in contrast and changes in colour.
Carlo Krier 