Tatami (originally meaning "folded and piled") mats are a traditional Japanese flooring. Made of woven straw, and traditionally packed with straw (though nowadays sometimes with styrofoam), tatami are made in individual mats of uniform size and shape, bordered by brocade or plain green cloth. Tatami were originally a luxury item for the wealthy at a time when lower classes had mat-covered dirt floors. Tatami were gradually popularized and finally reached the homes of commoners towards the end of the 17th century.