Since jdphotochem is shutting its doors, Nymoc in Toronto will be my go to place for Canadians as I cannot find anyone else. They carry both Postassium Di-Chromate and Ammonium Di-Chromate.
Email: nymoc@bellnet.ca
Phone: 416-465-1929 (ask for John)
Email: nymoc@bellnet.ca
Phone: 416-465-1929 (ask for John)