A superdollar (also known as a superbill or supernote) is a very high quality counterfeit United States one hundred-dollar bill, alleged by the U.S. government to have been made by unknown organizations or governments. In 2011, government sources stated that these counterfeit bills were in "worldwide circulation" from the late 1980s until at least July 2000 in an extradition court case. While there are many features on supernotes that can be detected with today's technology, new, more sophisticated supernotes are always being produced. No current technology can guarantee catching 100% of the supernotes in circulation. Various groups have been suspected of creating such notes, and international opinion on the origin of the notes varies. The U.S. government believes that North Korean officials have passed off supernotes in various countries and accuses North Korea of producing them. Over $35 million worth of counterfeit $100 bills were produced by British criminals, who were arrested in 2002. A new $100 bill design intended to thwart counterfeiting, incorporating a "3D security ribbon", color-shifting numerals and drawings, and microprinting, entered circulation in 2013. Production Supernotes are said to be made with the highest quality of ink printed on a cotton/linen blend, and are designed to recreate the various security features of United States currency, such as the red and blue security fibers, the security thread, and the watermark. Moreover, they are printed using an intaglio printing process or with engraved plates, the same process used by the Bureau of Engraving and Printing (BEP) of the U.S. government for legitimate notes. In most counterfeiting, offset printing or color inkjet and laser printing are most common means of making counterfeit money. Experts who have studied supernotes extensively and examined them alongside genuine bills point out that there are many different varieties of supernotes. In 2006 the "family" of fraudulent bills was thought to have 19 members. However, producers of the supernotes have improved the product since 2006, and more varieties exist. Early versions of the fake notes, for example, lacked the bands of magnetic ink printed in distinctive patterns on different denominations of U.S. money; later counterfeits rectified this error. Several of the inconspicuous "mistakes" on the first supernotes were corrected, some several times. On the genuine $100 bill, for example, the left base vertical line of the lamp post near the figure on the reverse of the $100 note is weak. The first supernotes printed this