Helvetica is a sans serif typeface of Swiss origin. Although typefaces without serifs were used in the nineteenth century, it was not until the twentieth century that they became popular. In 1957 the Haas foundry introduced Haas Grotesk, designed by Max Miedinger (with Eduard Hoffmann), later to become known internationally as Helvetica. Helvetica's large x-height, slightly condensed letters, and clean design make it a very readable typeface. In general, sans serif typefaces have relatively little stress, with optically equal strokes, and should always be leaded.