US Unveils New $100 Bill Today
After production problems and delays, the Federal Reserve will finally circulate a new $100 bill today. The aim of the redesigned bank note is to make it harder to fake.
Due to the enhanced security features “it only takes a few seconds to check the new $100 note and know it’s real,” according to Newmoney.gov, a website affiliated with the Federal Reserve Board,Treasury Department and U.S. Secret Service.
Check out a decade’s worth of research and development that went into America’s newest bank note.:
Blue 3-D Security Ribbon: The blue ribbon to the right of Benjamin Franklin is woven instead of printed on the paper. Tilt the note back and forth and the blue ribbon shows “Liberty like bells” transforming into “100s,” When you tilt the note back and forth, the bells and “100s” will move side to side. Tilt the bill side to side, and the images move up and down.
Raised Printing: Stroke Benjamin Franklin’s left shoulder and it will feel rough to the touch due to an enhanced intaglio printing process. 
Serial Numbers: Each note has a unique combination of 11 numbers and letters that appears on the front of the bill twice. These specific and original serial numbers aid law enforcement in identifying counterfeit notes.
Bell Hiding in an Inkwell: Inside the copper-colored inkwell is a bell that changes from copper to greenish hue when tilted.
Portrait Watermark: Hold the note to light and look for a faint image of Benjamin Franklin in the blank space to the right of the portrait. The image is visible from either side of the note.
Security Thread: If you hold the note up to light you will see an embedded thread of the letters ‘USA’ and the number ‘100’ running vertically on the note. Under ultraviolet light the thread glows a pinkish hue.
Look for the Gold: There is a large gold numeral ‘100’ on the back of the note. This addition is designed to help individuals with visual impairments to read the denomination.
And some other features, not tied specifically to security:
New Color: The background color is a pale blue but don’t rely on this feature to check the note’s authenticity. Instead, scroll down to check out how the serial numbers aid against counterfeiting.
American Symbols of Freedom: U.S. symbols of freedom addition includes phrases from the Declaration of Independence and the quill used by the Founding Fathers to sign the document.
Federal Reserve Bank Indicator: The Federal Reserve System is represented by a universal seal that is to the left of Benjamin Franklin’s portrait. A letter and number identifies the issuing Federal Reserve Bank — there are 12 regional Federal Reserve Banks and 24 branches located in major U. S. cities.
Printing Locator: The new $100 notes are printed in either Washington, D.C., or Fort Worth, Texas. If the bill is printed in Fort Worth, it will have a small ‘F.W.’ in the top left corner on the front of the note. 
Source: Media