The Jewish Theological Seminary's "Micrography" exhibit showcases visual art, mostly from the 19th and early 20th century, made from ancient Hebrew religious texts and contemporary Jewish writings of the time.
Shown here: Postcard, Zadoc Kahn, Chief Rabbi of Paris (1839-1905). "Popular postcards featuring the micrographic portraits of renowned rabbis were produced in Europe at the beginning of the twentieth century. The portrait of Rabbi Kahn, formed from a French text, is drawn from his writings."
Found on the wonderful Text Mode tumblr.