From Seattle to Santa Croce sull'Arno to learn about the secrets of purification and industrial eco-compatibility: visit to the Aquarno treatment plant and the Ecoespanso plant for a delegation from the University of Washington involved in an international project of studies about the excellence of Made in Italy. From art to technology, from Venice to Rome and Florence: the visit to Santa Croce sull'Arno was a part of a study-tour that the students have made between artistic sites and cutting-edge industrial districts in Italy, among these the Tuscan tanning district for a cross-section on the ability to innovate both in terms of production and environmental compatibility (the Tuscan one is the only Italian tanning district with EMAS certificate). Accompanied by the teachers Ryan Kelly and Cecilia Strettoi, the students first visited the Sciarada tannery, where they followed the entire industrial tanning process , then stopped at the Aquarno and Ecoespanso, for a study session on the recovery processes of the by-products of tanning.