sign on, 1  to employ; hire. 2  to bind oneself to work, as by signing a contract: He signed on as a pitcher with a major-league team. 3  to start radio or television broadcasting, especially at the beginning of the day. 4  Computers. log1 (def 17a).
FROM FIBER TO FABRIC: ACETATE INTRODUCTION Initially invented in Europe as a varnish for airplane wings, acetate was first produced in the United States in 1924 making it the second oldest manufactured fiber.
This material was first used for eyewear in the late 1940âs because of brittleness and other problems with previously used plastics. Todayâs acetates are known for being strong, lightweight, and flexible. Cellulose acetate also has the widest range for transparency, rich colors, and finishes.