Kodak's website has a full data sheet on Xtol. It has an extremely thorough list of developing times for a variety of formats and a variety of dilutions. I have been satisfied with both 1:2 and 1:3 dilutions. Kodak recommends a minimum of 100 ml of stock Xtol per roll of film, whatever your dilution. Try some, it's great.(posted 8977 days ago)