“As soon as I set to work, [other ideas] seem to flow from the pen,” said Pablo Picasso. “To know what you want to draw, you have to begin drawing it.” History has it that the artist’s first word was “piz,” short for lápiz, Spanish for pencil. The son of an art teacher, Picasso began sketching at the age of seven, the start of his formal art training, and for the rest of his life used drawing to evolve ideas for larger works. He was particularly drawn to the buste de femme, a recurring subject through which his stylistic evolution, as well as his love life, can be charted. This exhibition puts 80 drawings by Picasso on view, works that span 70 years of his practice and move from charcoal to crayon to pencil to pastel to gouache, ink, and watercolors. —E.C.