WASHINGTON — The United States Treasury Department last week announced new measures aimed at protecting US currency from counterfeiting by advanced copier, scanner, and computer-based printer equipment. The new security safeguards, which will be almost invisible to the naked eye, are:Security thread. A polyester strip is embedded on the left side of the note's face, with the letters USA printed on the strip. This cannot be reproduced in the reflected light of copiers. Microprinting. "The United States of America" is printed alongside the portrait in letters legible only with a magnifier.