These Astorflex are crafted from buttery soft premium suede, using intricate hand-stitched detailing an.d natural outsole all made in Italy. Astorflex Materials: The lining and insoles are in vegetable-tanned calf leather, obtained by soaking the leather in a mixture of water and powdered oak bark and mimosa, without using dies or color finishes. This process makes the leather healthier, hypoallergenic and guarantees greater sweat absorption for dry, odorless feet. Most of our soles are in natural rubber consisting in coagulated latex from the rubber tree (hevea brasilianis). The various shoe parts are assembled using water-based adhesives.