For all bills except $1 and $2 dollar bills, there should be a security thread (plastic strip) running from top to bottom.  The thread is embedded in (not printed on) the paper and runs vertically through the clear field to the left of the Federal Reserve Seal.  On authentic bills, this should be easily visible against a light source. The printing should say "USA" followed by the denomination of the bill, which is spelled out for $10 and $20 bills but presented in numerals on the $5, $50 and $100 bills.  These threads are placed in different places on each denomination to prevent lower-denomination bills being bleached and reprinted as higher denominations. You should be able to read the inscriptions from both the front or back of the note.  Also, it should only be visible against a light source. Plastic strips in high-denomination bills should glow a specific color.  The $5 dollar bill should glow blue; the $10 bill should glow orange; the $20 bill should glow green; the $50 bill should glow yellow; the $100 bill should glow pink. If your bill remains white under a black light, it is likely a counterfeit. Use natural light to see if your bill bears an image of the person whose portrait is on the bill.  Hold the bill up to a light to check for a watermark.  A watermark bearing the image of the person whose portrait is on the bill can be found on all $10, $20, $50, and $100 bills series 1996 and later, and on $5 bills series 1999 and later. The watermark is embedded in the paper to the right of the portrait and should be visible from both sides of the bill. Color shifting ink is ink that appears to change color when the bill is tilted.  Color-shifting ink can be found on $100, $50 and $20 dollar bills series 1996 and later, and on $10 dollar bills series 1999 and later. $5 and lower bills do not yet have this feature.  The color originally appeared to change from green to black, but it goes from copper to green in recent redesigns of the bills. This includes small words or numbers that are hardly visible to the naked eye and cannot be read without a magnifying glass.  Beginning in 1990, very tiny printing was added to certain places (which have periodically been changed since then) on $5 and higher denomination bills. Don't worry about a specific location.  Since micro-printing is hard to duplicate, counterfeits usually tend not to have any. Counterfeits with micro-printing tend to have blurred letters or numbers.  On a genuine bill, the micro-printing will be crisp and clear.
ارفع الورقة النقدية تجاه الضوء. استخدم أشعة فوق بنفسجية (ضوء أسود) للاطلاع على أشرطة الأمان. تفقّد العلامات المائية. قم بإمالة الورقة للتحقّق من الحبر متغيّر اللون. تفقّد الطباعة الدقيقة.