Elaborately embroidered, the papal slippers are made by hand with red satin, red silk, and gold thread, and the soles are made of leather. The papal slippers feature a sewn cross of red rubies. Until the first half of the 20th century, it was customary for pilgrims having an audience with the pope to kneel down to kiss one of his slippers. Pope Benedict XVI has restored the tradition of the red outdoor papal shoes, similar to those worn by Paul VI.