Printing
The printing of Notes is about as technical and precise an operation as you would expect as it needs to be to ensure that your Notes are durable and that counterfeiters cannot easily produce fakes. During production, a Note might endure pressures as high as 20,000 Lbs. Per Square Inch (PSI). The process is utterly amazing.
While this is not a complete step-by-by guide to absolutely every aspect of the printing of Notes, these are the basics of what you need to know when it comes to Fancy Serial Numbers and currency collecting in general.

Paper.
The paper and ink used in the production of U.S. paper currency is as distinct as its design. The paper comes to the B.E.P. in brown paper-wrapped loads of 20,000 sheets (2 pallets of 10,000 sheets) From Crane & Co. Each of these sheets is tracked by the B.E.P. as it passes through the production process. The United States currency paper is composed of 75% cotton and 25% linen. This is what gives United States currency its distinct look and feel. For denominations of $5 and above, the security thread, and watermark are already built into the paper when it is received.

Ink.
All bills, regardless of denomination, utilize green ink on the backs. Front of the Notes, on the other hand, use black ink, color-shifting ink in the lower right-hand corner for the $10 denominations and higher, and metallic ink for the freedom icons on redesigned $10, $20, and $50 bills. The $100 note’s “bell in the inkwell” freedom icon uses color-shifting ink. These and the other inks appearing on U.S. currency are specially formulated and blended by the BEP. Inks headed for BEP presses also undergo continual quality testing. The Bureau of Engraving and Printing uses about 9.7 tons of ink a day.

Offset Printing Operations.
With the introduction of the redesigned $20s in 2003, subtle background colors were added to the currency to enhance the security. For these denominations, offset printing is the first printing that occurs on the “blank” paper. Offset Printing.
The background colors are printed by the BEP’s Simultan presses, which are state-of-the-art, high-speed, sheet-fed rotary offset presses. These presses are over 50 feet long and weigh over 70 tons. They are specifically designed to print security offset designs on currency paper. Using dry offset plates, ink from the plate is transferred to an offset blanket. The blank sheet of paper passes in-between the face and back blankets and simultaneously prints the complete image on the paper. The press has eight print units, four on the face and four on the back, with two comprehensive computer control consoles. Many of the press settings can be controlled from these consoles and their status is displayed on the computer screens. The press is capable of printing 10,000 sheets per hour; every 500 impressions, the press operators will pull a sheet and carefully examine it to ensure that all the colors are remaining consistent.

Intaglio Printing Operations.
Intaglio (pronounced in-tal-ee-oh) comes from an Italian word which means to cut, carve, or engrave.
Learning how to create a plate for the Intaglio press can take up to 15 years of apprenticeship for the engravers to actually start working on a die. A group of designers create one master die, this is either the front or the back and this process can take upwards of 8 months to do, then they take this master die and copy it through plastic transfer to create a full plate of either 32 or 50 notes, they then coat the plate in silver, give it an electric nickel bath for 24 hours, clean it up and bend it to fit the machine, then put it on a lathe to shave it to the proper thickness and after all this effort, the margin of error is only +/- 0.0003 (three ten-thousandths) of an inch. That is 1/10th the thickness of a human hair. In this image you see a plate that will press the ink onto the back of a $1 Note. Later in the process it will be bent perfectly to fit the drum on an intaglio press.

Back Intaglio Printing
Intaglio printing presses are used to print the green engraving on the back of U.S. currency. Blank currency sheets for the $1s and $2s or the offset printed sheets for redesigned currency are fed into these presses and printed at a rate of 10,000 sheets per hour.

Face Intaglio Printing.
On the newly designed Notes, the Intaglio presses operate like those used to print the back. Intaglio engravings are used to print the faces of the bills. While the same printing process applies, one difference is how the ink is applied to the engraving. Special cut-out ink rollers transfer the different inks to a specific portion of the engraving, thus allowing three distinct colors to be printed on the face of the note; the black for the border, portrait engraving, and signatures of the Secretary of the Treasury, and the Treasurer of the United States; the colorshifting ink in the lower right hand corner for the $10 denominations and higher; and the metallic ink for the freedom icons on redesigned $10, $20, and $50 bills or color shifting ink on the redesigned $100 Note’s freedom icons. Bills printed in Fort Worth, Texas, will also have a small “FW” printed in black ink while those printed in Washington D.C. will not have “FW” on the face.

Mechanical Examination.
Throughout the printing processes, minor printing imperfections may have occurred, either through printing or the handling process. To ensure only the highest quality sheets proceed to the numbering operation, the face and back of the sheets are thoroughly examined using state-of-the-art computer technology that can scan 20,000 sheets an hour.

UOCIS.
The Upgraded Off line Currency Inspection System, otherwise known as UOCIS, integrates computers, cameras, and sophisticated software to completely analyze an untrimmed printed sheet. By examining untrimmed sheets, the BEP is better able to monitor color registration and ink density.
As the sheets pass through the system at the rate of about 8,000 sheets per hour, a transmissive camera is used to inspect the paper by looking through the sheets to ensure the thread and portrait watermark are in the correct position. In addition, two separate cameras take a digital picture of both the front and back of the sheets, breaking the images down into four million tiny pixels. After the sheets are trimmed, a trim camera takes measurements of the sheets. All data is gathered from the sheets and compared to what is considered a perfect “golden image,” and within three tenths of a second, the computer decides if the sheet is acceptable or a reject, looking for defects such as ink spots, ink deficiencies, or smears.

Nota-Sav is the BEP’s examining equipment utilized to examine the $1 product line. Since those bills have neither a security thread nor a watermark, Nota- Sav does not need the technical sophistication of UOCIS. Using electronic examination “eyes” to inspect the sheets, these inspection systems provide the automated means to process the $1 bills as they move forward on a transport.

COPE.
COPE-Pak presses in this section utilize the letterpress printing process which is the third and final type of printing utilized by the BEP for paper currency. The acronym COPE-Pak stands for Currency Overprinting Processing Equipment and Packaging. These presses were custom designed specifically for the BEP and are the most automated equipment of their kind in the world. This press takes a 16-subject printed and examined sheet of currency and adds the two serial numbers, the black universal Federal Reserve seal, the green Department of the Treasury seal, and the corresponding Federal Reserve identification numbers. Serial numbers on the redesigned currency differ slightly from those on the old currency. The new serial numbers consist of two prefix letters, eight numerals, and a one-letter suffix. The first letter of the prefix designates the series (for example, Series 1996 is designated by the letter A, and Series 1999 is designated by the letter B). The second letter of the prefix designates the Federal Reserve Bank to which the note was issued. The serial numbers are overprinted in sequential order and remain in order until the 16-subject sheets are cut. In addition, a universal Federal Reserve seal replaces individual seals for each Federal Reserve Bank. On the other hand, $1 and $2 dollar notes have not been redesigned. Those notes still maintain the specific black Federal Reserve Bank seal. Finally, the green Department of the Treasury seal is printed on all denominations.

LEPE.
Large Examination and Printing Equipment, is the newest addition to the printing capabilities of the B.E.P. LEPE represents the newest generation in numbering and processing equipment for BEP.
In February 2014, BEP ushered in a new era by printing currency on 50-subject sheets versus 32 notes per sheet.
Sitting at 144 feet long, these mammoth machines are state-of-the-art, specifically designed for BEP, combining multiple currency production processes at once: full sheet examination, letterpress printing functions, product verification, and cutting and packaging currency. Currently, only $1 and $5 notes are produced in 50-subject sheet format. The $20 note is next in line for transition into the larger format and is scheduled to be in production by summer 2022.

1st printing, 2nd printing, and Overprinting.
In recent years there has been a lot of confusion to new collectors when it comes to the way The Bureau of Engraving and Printing does the printing. This comes into play with CS-Error Notes Chapter 26. If someone says their Note is a CS-Misaligned 1st printing then you will need to know the year of the Note. Beginning in 2003 with redesign and launch of the $20 Note, they changed the order and way that they printed Notes.
Prior to 2003 the Notes were printed in this order:
1st printing was the back plate, let dry for 72 hours,
2nd printing was the front plate, let dry for 72 hours,
3rd printing or overprinting was the serial numbers, federal seals, bank seals and series letters on the front. And, this was the same for all Notes: $1, $2, $5, $10, $20, $50, and $100.

The modern design was applied to the $5, $10, $20, $50, and $100 notes. Circulation of the new series began during the fall of 2003 with the introduction of the redesigned $20 note. It continued with the $50 note in 2004, the $10 note in 2006, the $5 note in 2008, and the $100 note in 2013.
1st printing. or offset printing. They print the background images on the front and the back of the Note. On a $100, this would be the all the little yellow 100s to the left of Franklin plus the ink well, golden quill, and constitutional writing on the right, as well as the overall background color of the Note. On the back, this includes the colored 100 and the blue background, then let dry for 72 hours.
2nd printing. They print the back of the Note which includes Independence Hall, all the borders, the two 100s on the left and the plate number, then let dry for 72 hours.
3rd printing. They print the front of the Note which includes Franklin, all the borders, the signatures (and if made in Fort Worth, they print the “FW”). They also print the color shifting ink on the ink well and print the color shifting 100 in the lower right hand corner, then let dry for 72 hours.
4th printing or overprint. They print the serial numbers, federal seal, universal bank seal, and series letters on the front, then let dry for 72 hours. CS-Straps, Bricks, Bundles, Cash Packs and Skids.

Note: Have you ever been watching a video on currency searching and heard them say, “I will be looking through 5 straps today.” or “I got a bundle; let us get searching.” These references are from the way the COPE system handles and packs the money. The order is as follows:
Name~COPE~Total~Number of Bills
CS-Strap 100 bills equal 1 strap 100 bills.
CS-Bundle 10 straps equal 1 bundle 1,000 bills.
CS-Brick 4 bundles equal 1 brick 4,000 bills.
CS-Cash-Pack 4 bricks equal 1 cash-pack 16,000 bills.
CS-Skid 40 cash-packs equal 1 skid 640,000 bills.

Security Features.
The redesigned notes retain the same size as previous notes and use similar portraits and historical images to maintain an American look and feel. Security features maintained in the enhanced Federal Reserve Notes include a portrait watermark visible when held up to a light, two numeric watermarks on the $5s, an enhanced security thread that glows under an ultraviolet light, micro printing, improved color shifting ink that changes color when the note is tilted, and on the newly redesigned $100 notes, a 3D security ribbon and enhanced, raised printing. While the percentage of counterfeit notes in circulation remains small, advances in technology have brought forth an increase in computer generated counterfeit notes. United States paper currency is redesigned to protect your hard-earned money by staying ahead of advancing technologies and tech savvy counterfeiters.

Security Features in depth.

Watermark.
Watermarks are images that are visible when you hold paper up to light and try to see through the Note. In U.S. Currency there are two types of watermarks: faces & numbers.

What the watermark is made of.
A watermark is that part of the paper where the watermark has been pressure treated to form the desired image of a face or a number 5. The pressure makes the paper thin in some areas and bunched up in other areas. The easier it is to see light through the paper the thinner the paper. The harder to see through or darker areas is where the paper has been bunched together. So if anyone tries to tell you it is an ink or tanning process of some kind, now you know.
Faces. On the $10, $20, $50, and $100 Notes, you will see the same image as the portrait of the person on that bill. The watermark picture of the person will be facing the same direction as portrait of the person and will be on the right side of the Note just a little below the center line or mid point of the Note.

Note:
Numbers on the $5 dollar Note, there will be a number 5 as the watermark. It will be a large number 5 on the right side of the Note at and just a little below the center line or mid point of the Note. Additionally, you will see three smaller number 5’s to the left of Lincoln’s portrait; they will be vertically aligned with one 5 at the center line or midpoint and one just above it and one just below it. Note: There are no watermarks on the $1 and $2 Notes.

U.V. Security Strips. U.V. Security strips are for lack of a better term “sandwiched” inside the paper, and when you hold the paper up to the light and look through the Note you can see this strip. It is in the $5, $10, $20, $50, and $100 Notes in various locations sometimes on the far left, just left of the portrait, just to the right of the portrait and farther right of the portrait, but the amazing thing about these strips is that they glow under black light and every bill has a different black light color.

Denomination~Reads~Symbol~U.V.~Color $5 5 Pointed ribbon w/ USA Blue.
$10 USA TEN U.S. Flag with 10 as stars Orange.
$20 USA TWENTY U.S. Flag with 20 as stars Green.
$50 USA 50 U.S. Flag with 50 as stars Yellow.
$100 USA 100 None Pink.

U.V. Strips placement.
Denomination~Placement
$5 Just to the right of the portrait.
$10 Just to the right of the portrait.
$20 Left of the left seal.
$50 Just to the right of the portrait, almost touching it.
$100 In between the portrait and the left seal.

Red and Blue Fibers.
There are red and blue fibers that are mixed into the pulp mix when the paper is being made. We think they want to keep what those fibers are made out of a secret as the current standard line is, “The paper is made out of 75% cotton and 25% linen and contains red and blue fibers mixed throughout.”
Somewhere before the 1990s, Crane & Co., the makers of the paper used to add shredded blue jeans and rags, all used, and they would add these to the mix and that is how the paper used to get its red and blue fibers, but now, we think it is a tightly held secret. On a history note, back in the early 1800s they used to add silk to the mix.

3D Security Ribbon.
This is a highly technical process, and we mean innovative. The closest we mere mortals can come to this is “lenticular printing.” You have most likely seen this printing on business cards, where you tilt the card from left to right and the image changes to another image or up to five images, or you tilt it up and down to generate this effect, but we mere mortals cannot do both on the same card.
The Bureau of Engraving & Printing use Liberty Bells and the number 100 as the internal holographic images. While lenticular printing takes thousands of pixels to create these images, The Bureau of Engraving & Printing uses over a million pixels to create a lenticular image that can move left to right and back, and up and down and back -- amazing!
The utterly amazing part of this is that it does not stop after five images. It will keep going from full tilt to the left to full tilt to the right, full bottom to top and back and all 180 degrees of tilting, and it will look like you are watching a video the entire time.
The Bureau of Engraving & Printing has stated that top counterfeiters have come about half way, but the image still stops at some point, so when inspecting a $100 Note go all the way left or right, all the way top to bottom, and a fake will stop moving at some point.
The holographic image will go the opposite direction as it is being moved. If you tilt the Note up and down, the image will go left and right, and the liberty bells will change into 100 and back. If you move the image right to left, the image will go up and down.

Color Shifting Ink.
In the bottom right-hand corner on the front face of the Note you will see the denomination of the Note. This denomination, such as a $20, will have color shifting ink.
When you look at this ink it will look copper in color, and when you tilt the note back it will turn to green, and it will do this on all newer $5s, $10s, $20s, $50s and $100s.
On the $100 Note there is an additional area of color shifting ink. It is to the right of the portrait, and is the Liberty Bell inside of an inkwell. The inkwell does not change color and will always look like copper. The liberty bell inside the inkwell starts as a copper color and when tilted back it changes to green.
Note: in the 1996 series of Notes this ink turns from green to black, and in the 2004 and later series of Notes it will turn from copper to green.

Micro printing. Micro printing is basically impossible to duplicate outside of the mint and extremely hard to see with naked eye. If you look at the micro printing under a microscope it is clear and easy to read. When counterfeiters try to reproduce micro printing, it is barely legible if at all. Where the micro printing is.

$100 Note:
“THE UNITED STATES OF AMERICA” is along Franklin’s vest collar directly below and to the left of Franklin’s chin.
The number “100” is within the vertical borders on the left and right. You will find “USA” repeated along the bottom of Franklin’s portrait.
You will find “USA100” repeated around the blank area that holds the watermark.
You will find “ONE HUNDRED USA” around the edges of the golden quill.

$50 Note.
“THE UNITED STATES OF AMERICA” is on Grant’s collar directly to the left of his chin at the beard line.
“FIFTY” is found repeated on the left and right borders.
You will find “FIFTY,” “50,” and “USA” in 2 of the stars that are to the left and right of the left black federal reserve seal.

$20 Note.
“THE UNITED STATES OF AMERICA 20 USA 20 USA” is in the border directly below and to the right of the treasurer’s signature.
You will find “USA” in the top of the “0” in 20 directly below the treasurer’s signature.
“20” can be found in between the “2”and the “0” at the top where they meet directly below the treasurer’s signature.
You will find “USA 20” on the bottom and right sides of the first three letters of the blue “TWENTY” and “USA” that are just left of the green federal reserve seal on the right side of the Note.

$10 Note.
“THE UNITED STATES OF AMERICA TEN DOLLARS THE UNITED STATES OF AMERICA” is below the portrait and above “HAMILTON” in the name plaque.
“THE UNITED STATES OF AMERICA TEN DOLLARS USA” is repeated and next to the borders on the left and right side.
You will find “USA 10” repeated around the base of the red torch just left of Hamilton’s chin.

$5 Note.
“E PLURIBUS UNUM” on top of the eagle’s shield, right of the portrait.
You will find “USA” between the columns of the eagle’s shield.
You will find “FIVE DOLLARS” along the left and right-side borders.
On the back of the $5 Note, you will find “USA FIVE USA FIVE” in the large purple 5.
On the back, you will find “ARKANSAS MICHIGAN FLORIDA TEXAS IOWA WISCONSIN CALIFORNIA MINNESOTA OREGON KANSAS WEST VIRGINIA NEVADA NEBRASKA COLORADO NORTH DAKOTA” just below the roof line of the memorial.
On the back you will also find “DELAWARE PENNSYLVANIA NEW JERSEY GEORGIA CONNECTICUT MASSACHUSETTS MARYLAND CAROLINA HAMPSHIRE VIRGINIA NEW YORK” just above the support columns on the memorial.

Circles of the eyes.
Circles of the eyes. Circles on currency were a decent anti-counterfeiting measure. The reason for this is that when scanners and photocopiers first came out, most scanners had trouble copying concentric circles and instead of reproducing a circle they would produce a figure 8 pattern. So, in response, The Bureau of Engraving and Printing added concentric circles to the Notes. These are in and around the eyes in the portraits, so if someone copied the notes, the eyes would be printed as figure 8s and be noticeably off.

Portrait background.
On older currency, and on $1 and $2 dollar Notes, some printers will see the lines in the background differently than you and I do, and when printing, the back ground will have a plaid or a checkerboard pattern that is very noticeable to the naked eye.

U.S. currency ink is magnetic, and will react to a magnet. If you hold a Note from a corner, and let the long end dangle downwards, then hold a strong magnet close to the bottom of the Note, it will move towards the magnet.

EURion Constellation.
In, on, or around 1996, a secretive plan to stop scanners and printers from copying or printing protected documents was hatched, and incorporated in such devices. The idea was simple; add in a pattern of circles arranged in such a way that, when detected by the scanner, it would initiate a stop scanning/printing order to the machine, in essence, a kill order.
The term “EURion constellation” was coined by Marcus Kuhn, PhD, a security researcher that uncovered this process when he failed to copy a European Union bank Note on a later 1990s scanner. The pattern he discovered was that of the Orion constellation hidden in the seemingly random “10s” that were on the Note. When he saw that there were small circles (the zeros in the 10s) arranged the same as the Orion constellation, he found that covering the constellation would allow printing to proceed.

Counterfeit Deterrence System.
The Central Bank Counterfeit Deterrence Group in 2003 created the Counterfeit Deterrence System (CDS) and has gotten this system into everything: scanners, printers, image editors, etc. While in the beginning it relied on the EURion constellation, it has gone far beyond that since then, detecting digital watermarks and more to the point that even a very small part of a Note will be detected as currency and a kill order will be initiated.

Note: This page contains excerpts and basic information from the book "The Green Guide to Fancy Serial Numbers". Please consider adding a copy to your library, thank you.