About

Olivia Trujillo

March 15, 2018

Winter 18, DES 40A

Professor Cogdell

Raw Materials of the 100$ Bill

For hundreds of years, the United states has been heavily dependent on paper currency or bank notes.  Yet, in societies’ reliance on technology today, digital goods are replacing tangible objects.  Paperless transactions are becoming more precedent especially with the use of banking apps such as, PayPal and Apple Pay. While there is a significant decline in the need of solid cash, the U.S. has doubled their printing of currency in the past ten years[1]. After researching the life cycle of the 100-dollar bill, it became shockingly apparent that the United States currency is far from sustainable nor renewable. The acquisition of raw materials for the 100-dollar bill, such as cotton, linen and ink, are not cost effective. Currently the U.S. One-hundred-dollar bill costs 13.2 cents to make[2]. The two major raw materials, cotton and linen, have increased the production cost of each one- hundred-dollar bill by 60% since 2013[3] therefore, we need to find alternative materials or methods to not only reduce the cost but as well as the consumption.  

The main raw material that goes into the 100-dollar bill is cotton. 75% of the 100-dollar bill is made up of cotton.  The cotton that goes into the 100-dollar bill is grown across the “Cotton Belt”. The Cotton Belt stretches across seventeen states in the southern half of the Unites States, all the way from Virginia to California. Cotton takes on average 180 days from seed to harvest, which is the longest duration of annual crops in the Unites States. [4]

Texas produces the majority of cotton grown in the U.S, which is 4.5 million bales of cotton annually. According to the National Cotton Council of America, on average for US Currency we use 10,308,370 lbs. of cotton or 21,476 bales. Just for the 100$ bill alone we use 2,949,780lbs. of cotton or 6,145 bales. One bale of cotton makes exactly 313,600 100-dollar bills. [5]

            After the cotton is harvested it is then sent to Crane & Co. in Massachusetts, where they have been manufacturing all US currency since 1879.

The second raw material that makes up for 25% of the 100-dollar bill is linen, derived from flax seeds. All flax is grown in Belgium by farming company, Vervaeke Fibre. Vervaeke Fibre exclusivity grows its flax for United States currency. Vervaeke Fibre signed a contract with Crane &Co. in 1950 stating that they would only supply their flax to the US.[6]  Over the past 70 years there hasn’t been any significant American competition for flax, CEO of AgriBiz Jody Martin states,

“It will be a long time before Vervaeke faces U.S. competition. In the last 15 years, American farmers, primarily in South Carolina, have grown more flax. But there is no “near or even distant future competition for the suppliers to the paper industry[7].”

When the value of the Euro is higher than USD, I don’t see how purchasing flax from Belgium is cost-effective for Americans. If the United States produces more flax seed in the south, I don’t understand why that flax wouldn’t be used for our currency. If Crane & Co. were to switch over to American farmers they could save significant amounts of money in shipping and possibly labor.  

Lastly the ink and dyes that go into making US currency and the 100- dollar bill were difficult to find, due to the government trying to prevent counterfeiting. The ink that goes into making the 100-dollar bill is an oil- based ink. However, in my research I did find that the United States uses an ink called Optical Variable Ink or OVI. OVI is only made in Lausanne, Switzerland by a company called SICPA.

“Throughout its history, SICPA has dedicated itself to helping governments, central banks, high-security printers and industry find comprehensive solutions to widespread security issues. In a world where no document or product is immune to counterfeiting, alteration or smuggling, our business has expanded from protecting most of the world’s currency to providing secured identification, traceability and authentication solutions and services[8].”

In an optical variable ink can be seen in more than half of the 100-dollar bill; from the ‘100’, Liberty Bell, The U.S. Seal, and to the blue security ribbon.  This particular OVI is, “a multilayer thin film structure that provides a green-to-gold color shift and where in the pigment is a yellow blocking pigment[9].” With further research, I found the original patent on OVI defining the process on how this ink is made and applied;

 “An optical variable ink obtains a color shift between two distinct colors at first and second angles of incident light, an ink vehicle and optically variable flakes disposed in the ink vehicle, the optically variable flakes being comprised of a multilayer thin film interference structure having first and second parallel planar surfaces, the optically variable flakes having physical dimensions such that when the flakes are measured in directions parallel and perpendicular respectively to the planar surfaces an aspect ratio of at least 2 to 1 is provided, the multilayer thin film structure being of symmetrical design and including a metal reflector having first and second surfaces parallel to the first and second parallel planar surfaces at least one period disposed on each of said first and second surfaces of the metal reflector, each period being comprised of a dielectric layer with an index of refraction of 1.65 or less and a semi-opaque layer[10].

The pigmentation for the rest of the 100-dollar bill has very little information. The information I found is very brief explaining that a green dye is added to the cotton and linen mixture then black ink is used for the images of Benjamin Franklin and Independence Hall. Although black ink is made from soybean oil, carbon, and titanium dioxide[11] there is no actual proof that these materials are specially used in printing the 100- dollar bill.

             Since the production and of cotton, linen and ink is substantial, the United States could see a benefit in using electronic money. Although cotton is the cheapest material, its production cost is too high. Linen is pointlessly being exported out of Belgium, when North and South Carolina are producing flax at the same, if not higher rate. Mysterious special ink, OVI, is being transported across seas from the Swizz Alps. The acquisition of these raw materials are not cost-effective for the American tax payer. Using alternatives such as Apple Pay or PayPal could drastically reduce the cost of producing and importing these materials. However, extracting and producing these resources only out of the United States would be a more realistic and economical option.

Bibliography

Albena Shkodrova. “There's a Little Bit of Belgium in Every U.S. Dollar Bill.” Mental Floss, Latitude News, 20 June 2012, mentalfloss.com/article/30969/theres-little-bit-belgium-every-us-dollar-bill.

BOARD OF GOVERNORS of the FEDERAL RESERVE SYSTEM. “How Much Does It Cost to Produce Currency and Coin?” Board of Governors of the Federal Reserve System, 6 Mar. 2018, www.federalreserve.gov/faqs/currency_12771.htm.

INC, Flex Products. “Patent on Optical Variable Inks.” Google Patents, Google, 22 Oct. 1991, patents.google.com/patent/US5059245.

Jones, Chris. “A Hundred Bucks Says You Won't Read This Story.” Esquire, Esquire, 7 Oct. 2017, www.esquire.com/news-politics/a24292/benjamin-hundred-dollar-bill-0913/.

National Cotton Council of America. “Cotton and U.S. Currency.” Cotton and U.S. Currency, www.cotton.org/pubs/cottoncounts/cotton-currency.cfm.

National Cotton Council of America. “Crop Production.” Cotton: From Field to Fabric- Crop Production & Planting, www.cotton.org/pubs/cottoncounts/fieldtofabric/crops.cfm.

Ritter , Steve. “Ink.” Chemical & Engineering News, American Chemical Society, 16 Nov. 1998, pubs.acs.org/cen/whatstuff/stuff/7646scit2.html.

“SICPA History.” SICPA, www.sicpa.com/sicpa-history. 

Christina Determan

DES 40A

Professor Cogdell

10 March 2018

The Life Cycle of the One Hundred Dollar Bill: Embodied Energy

One item has been, and still is, an integral part of the “American Dream” that people around the world recognize.  U.S. currency, the item that funded the American Revolution, playing a crucial role in the birth and continuing existence of the United States of America, is a staple in everyday life for many.  However, in today’s ever growing dependency on technology, physical goods are often recast as digital products.  This pattern is especially prevalent during monetary exchange with the new availability of cashless transactions through credit cards and other means. Although there has been a decline in the need and use of physical cash,  U.S. currency is still being printed when most purchases are processed electronically. In order to determine whether the allocation of generated power is effectively used during the manufacturing of cash, the main focus will be put on the note with a high global demand and one of the largest quantity of prints, the one hundred dollar bill.  Although the one hundred dollar bill has the longest lifespan among the other denominations of bills,  resources going towards the production of this are not being used efficiently when energy used throughout the acquisition of raw materials, design, printing, circulation, and disposal of the one hundred dollar bill is taken into account.

Even before the physical bill is printed, the life cycle has already begun with the consumption of energy through the harvesting of raw materials. Cotton, linen, and ink are the major components that make up the one hundred dollar bill.  Machines are used for the harvesting of cotton, known as cotton pickers, which display chemical energy due to the fact that they our powered by the burning of gasoline.  A popular model of the cotton picker, manufactured by John Deere, has a three hundred seventy gallon fuel tank, giving it the ability to harvest an estimated ten acres of cotton per hour for a total of twelve hours, on a full tank.  Next, in order to produce linen, kinetic energy is used in the harvesting of flax, the plant that linen is made from, by the pulling of flax from the ground.  After, electromagnetic energy is used to dry out the flax, by leaving it out in the sun in order to prepare the fibers to create linen. Lastly, kinetic energy is used once again during the spinning of the flax fibers to produce linen.  Finally, the last integral component, ink, is produced by the Bureau of Engraving and Printing itself.  Chemical energy is used in the combination of black, green, metallic, and color-shifting inks to create the unique, hard to counterfeit, pattern of ink used to print on the bill.

Although large amounts of energy has already been expended on the gathering of resources, the printing process of the one hundred dollar bill is an extremely detailed and complicated process.  The current design process replaces simple tools, such as a pencil and pen, with digital means, allowing for energy used in the manufacturing of paper, pencils, pens, and other physical tools, to be reallocated to the production of  a single computer that in turn develops a digital design.  After the design is created, the image is required to be engraved in order to create the printing plates that are essential for the mass production of the bills.  During this step, kinetic energy is used by the engraver, who physically cut and shape steel dies, who also employ chemical energy by using acids to create finer details.  After, kinetic energy is used by the transfer press to transfer the engraved images to a printing plate by exerting four tons per square inch of pressure.  Then, after the “master” printing plate is made, chemical energy is used to create copies of the plate through the use of silver nitrate and nickel salt solution.  Chemical energy is also used in the creation of the paper in order to combine the cotton and linen fibers.  On average, 0.45 million GJ of electricity is used in the production of the special paper used to produce money every year.  During the actual printing process, 0.35 million GJ of electricity is used every year.

An essential part of the lifecycle of the one hundred dollar bill is allocating physical amounts of cash in certain locations, whether it be banks or private reserves, in order for it to be accessed and distributed among the public. Whether money is being transported or stored, energy is constantly used to power vehicles and preserve the bill before and during distribution.  Kinetic energy is used in the distribution of money from the Federal Reserve to the banks under it. More kinetic energy is used in the distribution of money from the larger banks to the smaller banks and then to people, who then continue to use kinetic energy to use the bills in physical transactions. On top of that, there is a combination of both kinetic and electrical energy used when people choose the option of obtaining money from an ATM since it must use electricity in order to be powered, about 135 kWh per month, and physical bills are being transferred in and out of the machine.

The average lifespan of a one hundred dollar bill is fifteen years, meaning that the worn out, unusable bills have to be discarded at some point in time.  Shredding is necessary in preventing the creation of counterfeit bills, creating a situation where the use of energy towards the stripping of bills is inevitable.  Once a bill becomes worn and must be removed from circulation it is transferred to the Federal Reserve, where kinetic energy and electrical energy is implemented by a machine that scans the quality of each bill and shreds the bills unfit for circulation.  One version of the machine is able to sort 76,000 banknotes per hour. The power consumption used by this machine is on average 3.3 kW.  Finally, after the money is shredded, chemical energy is used to break down, or combine, the shreds with other materials to be recycled into new products such as roofing tiles, fuel, stationary, packing material, and souvenirs.

The electronic option of banking is more efficient and sustainable, since creation of electronic currency and transactions take minutes (limiting the amount of energy being used), when compared to the large quantity of energy used throughout each stage of the physical creation of bills.  On top of that, if every one hundred dollar bill was converted into a digital version, with each new bill added to circulation the production of an extremely complicated physical rendering of the currency will not be needed, only the energy used to power the computer used to create it. There would be no necessity of the creation and transporting of specialized paper and ink, while almost completely eliminating the design, making of plates, and printing processes altogether.  More importantly, if all these processes are eliminated, less waste will be produced, since currency is no longer made out of a tangible cotton-linen blend paper, therefore no energy will be needed to be expended in order to dispose, with the use of transportation, or repurpose the shreds. The annual disposal of seven thousand tons of United States currency can be completely avoided, conserving not only the energy used to transport the waste to landfills, but also the energy throughout the process all the way to the beginning of the lifecycle with the growing and harvesting of both cotton and flax crops.  In the end, a complete transfer to electronic banking will allow for a refocus of energy solely on providing enough power to a single computer that can generate and transfer currency through digital means.

Bibliography

Calvin Sims. “In Recycling of Greenbacks, New Meaning for Old Money.” The New York Times,

The New York Times, www.nytimes.com/1994/05/22/us/in-recycling-of-greenbacks-new-meaning-for-old-money.html.

“Currency Print Orders,” BOARD OF GOVERNORS OF THE FEDERAL RESERVE

SYSTEM, https://www.federalreserve.gov/paymentsystems/coin_currency_orders.htm

“Designing” U.S. Bureau of Engraving and Printing, U.S. Department of the Treasury,

www.moneyfactory.gov/hmimdesigning.html.

“Diebold Innovation Leads to World's Greenest, Most Power-Efficient ATM.” Cision,

PRNewswire, 17 Mar. 2014, www.prnewswire.com/news-releases/diebold-innovation-leads-to-worlds-greenest-most-power-efficient-atm-250600621.html.

“Engraving” U.S. Bureau of Engraving and Printing, U.S. Department of the Treasury,

www.moneyfactory.gov/hmimengraving.html.

“Follow the Benjamins,” The Wall Street Journal, Dow Jones & Company Inc.,

https://www.wsj.com/articles/SB10001424052748703709804575202270657107814

“High Performance Banknote Processing Systems.” Banknote Processing Systems | G+D,

Giesecke+Devrient Currency Technology GmbH,    www.gi-de.com/en/us/currency-technology/solutions/cash-processing-solutions/banknote-processing-solutions/.

“How Cotton Is Grown.” The Story of Cotton, www.cotton.org/pubs/cottoncounts/story/how.cfm.

“How Long Is the Lifespan of U.S. Paper Money?” Board of Governors of the Federal Reserve

System, www.federalreserve.gov/faqs/how-long-is-the-life-span-of-us-papermoney.htm.

Indiviglio, Daniel. “The Destruction of Money: Who Does It, Why, When, and How?” The

Atlantic, Atlantic Media Company, 8 Apr. 2011, www.theatlantic.com/business/archive/2011/04/the-destruction-of-money-who-does-it-why-when-and-how/236990/.

“John Deere Updates Revolutionary Cotton Picker with CP690 in 2015.” John Deere, Deere &

Company, www.deere.com/en_US/corporate/our_company/news_and_media/press_releases/2014/agriculture/2014aug4_cp690.page.

“Linen.” How Products Are Made, Advameg, Inc., www.madehow.com/Volume-4/Linen.html.

McCook, Hass. “Under the Microscope: The Real Costs of a Dollar.” CoinDesk, 5 July 2014,

www.coindesk.com/microscope-real-costs-dollar/.

“Paper and Ink” U.S. Bureau of Engraving and Printing, U.S. Department of the Treasury,

www.moneyfactory.gov/hmimpaperandink.html.

“Plate Making” U.S. Bureau of Engraving and Printing, U.S. Department of the Treasury,

www.moneyfactory.gov/hmimplatemaking.html.

Pamela Munoz

Design 40 A

March 13, 2018

Professor Cogdell

Winter 2018

How Green is Our American Green?

Many of us never question the methods in which our government decides to manufacture our currency; possibly because we trust that our government makes decisions based on the people’s well-being. While studying the life cycle of the newest version of the 100$ bill, it came to my attention that the production of our American currency is far from sustainable. The emission of waste when extracting and manufacturing raw materials of the one-hundred-dollar bill, such as cotton, linen and ink, are mainly caused by the dependency of mechanical machinery and water. Consequently, contributing to the global warming crisis that our world is facing today. America’s currency is a vital factor that allows our country to maintain its economy, on that note, we should investigate ways in which we can best make use of resources and find alternatives to alleviate the global warming contribution that our current currency is making.

        The one-hundred-dollar bill is composed of cotton, linen and ink. Both cotton and linen are natural crops, which might trick many to think that because these are naturally found within nature, it makes our paper money sustainable. However, the processes that these crops must go through in order for the Bureau of engraving and printing of the U.S. Department of the Treasury is able to use them, is very harmful to our environment. Seventy five percent of the composition of the one-hundred-dollar bill is made up by cotton. The cotton crop fields are heavily reliant on a very important finite resource, water. To put it into perspective, cotton fields in China took over ninety seven percent of the water of the Indus River, one of the largest rivers in Asia. Moreover, the process of growing cotton, uses sixteen percent of the pesticide, insecticides and herbicides that is available in the world. These harmful chemicals get washed out of the soil, causing pollution in our rivers and groundwater. Unfortunately, the massacre does not stop there, the continuous use of pesticides kills massive numbers of pests, creating a disproportion on the biodiversity of our ecosystem. In addition, cotton also uses industrial fertilizers. The production of these fertilizers takes up 1.5% of the world’s energy consumption, resulting in carbon dioxide emission into our atmosphere. Finally, through the high amounts of nitrate that are involved in the agricultural field, it eventually turns into nitrous oxide, also known as laughing gas.  Speaking of Global warming, nitrous oxide is a chemical that is 300 times more harmful than the carbon dioxide. (organiccotton.org) On that note, we can see that the process that the cotton over goes to contribute to the making of our American currency is quite fatal to our environment.

        The second material that composes twenty five percent of the one-hundred-dollar bill is linen, which comes from flax seeds. Through investigating this crop, I found out that it is far more sustainable than cotton. Flax is a crop that does not require much water, pesticides, low energy consuming and as linen it is stronger than cotton. However, unfortunately linen is only responsible a small percentage of the composition of our currency’s paper. Furthermore, the linen that we use to manufacture the one-hundred-dollar bill, mainly comes from the linen leftovers that are not convenient to generate linen fabric. This might make one think that it contributed to a sustainable currency, nonetheless the linen fibers must go through a chemical intensive process that could make you think otherwise.

        A study conducted by undergraduate students at the Vermont University states: “Before these fibers can be used they must be refined chemically and mechanically to remove impurities such as natural oils. This is done by first cooking the fibers in sodium hydroxide. In solid form NaOH is not mobile in soil, however, it dissolves easily in water and can be leached into soils, causing water contamination. Also, the fumes produced are highly toxic and can result in skin, eye, nose, and throat irritation (Lenntech). Sodium hypochlorite (used in bleach) is used to brighten the color of the fibers. NaOCl, when mixed with acids, creates a toxic chlorine gas. NaOCl is also acutely toxic to fish (Labour Environmental Society).”  (A Sustainability Assessment of U.S. and Australian Currency)

        Through this research we can see that the process that allows the BEP to use the linen fibers for our currency is quite long and harmful. The transformation of linen, releases detrimental toxics that create social health problems for the workers, it pollutes water which is one of our most important limited resource, consequently becoming a threat to marine animals.

        Finally, the third component of America’s currency is ink. There are three different inks used within our newest one hundred dollar bill. These include:  optically variable ink, black ink and green dye. Optical variable ink, is used in the new currency as a security system against counterfeit. While looking at the OVI patent, I came across the challenge to find out what it was made out of and if it had any effect on the ability to recycle paper of the bill. Unfortunately, the composition information of this kind of ink was not very informative. I believe this might be the case for security reasons. However, I did find out that OVI is a water based ink, compared to others that are oil based. By making it water based, it allows the ink to become waterproof when it is dried.

Through pubs.acs.org, I was able to find out the composition of the ink. Which states the following: “Color printing inks are made primarily with linseed oil, soybean oil, or a heavy petroleum distillate as the solvent (called the vehicle) combined with organic pigments. The pigments are made up of salts of multiring nitrogen-containing compounds (dyes), such as yellow lake, peacock blue, phthalocyanine green, and diarylide orange. Inorganic pigments also are used in printing inks to a lesser extent. Some examples are chrome green (Cr2O3), Prussian blue (Fe4[Fe(CN)6]3), cadmium yellow (CdS), and molybdate orange (a mix of lead chromate, molybdate, and sulfate).”

Black ink is made using carbon black. And white pigments, such as titanium dioxide, are used either by themselves or to adjust characteristics of color inks. Inks also contain additives such as waxes, lubricants, surfactants, and drying agents to aid printing and to impart any desired special characteristics.”

As we can see the manufacturing of the ink used in the one-hundred-dollar bill is highly chemically composed. This lead me to think that it could possibly affect the biodegradability of a bill.

After extensive research, I came across the only article that talked about this matter, greenhome.com. This resource stated the following: “Another problem with composting paper is the ink: products like magazines and wrapping paper sometimes use inks with metals or other dangerous substances in them which will stick around when they’re composted. In general, though, paper products can easily be thrown into a home compost bin.” Making me conclude that the use of highly processed ink in our American currency, is tough to biodegrade. This is beneficial in the terms of durability, however when the lifespan of this item is over it will be difficult to find ways to recycle or compost it.

As we can see, there is many factors within the manufacturing of the one-hundred-dollar bill that contribute to the contamination of our environment. Following up on that idea, the prime mover for the fabrication of our paper currency is heavily reliant on mechanical machinery. These machines include: Industrial printer, cutter, computer to produce the security codes, inspection machine for quality control, and washing machine to test durability. Subsequently, because of the high reliance in electricity powered machine, we are contributing to the emission of carbon dioxide into our atmosphere; polluting our air.

In addition, the transportation of our currency throughout all the banks across the country, is done primarily by trucks. Unfortunately, this adds to the list of waste emissions created by the production of the one-hundred-dollar bill. The following segment of the United States Environmental Protection Agency website, briefly describes the effects of transportation and global warming effects:

“Burning fossil fuels like gasoline and diesel releases carbon dioxide, a greenhouse gas, into the atmosphere. The buildup of carbon dioxide (CO2) and other greenhouse gases like methane (CH4), nitrous oxide (N2O), and hydrofluorocarbons (HFCs) is causing the Earth’s atmosphere to warm, resulting in changes to the climate we are already starting to see today.  

wenty-seven percent of U.S. greenhouse gas (GHG) emissions is from transportation. Transportation is the second leading source of GHG emissions in the United States, just behind electricity. Between 1990 and 2015, GHG emissions in the transportation sector increased more in absolute terms than any other sector.”

Finally, when the lifespan of the one-hundred-dollar bill has ended, the U.S. Department of Treasury shreds the old currency to later sell it as souvenirs.  Five pounds of shredded U.S. Currency, roughly about $10,000 worth, is sold for forty-five dollars. I believe the BEP had a difficult time finding a way to recycle our currency, because of all the chemical processes that go into making it. For example, the waterproof security ink OVI, makes it difficult for our paper bills to be recycled while still being cost effective.

In conclusion, people expect governmental policies and intentions to be positive. After all it's called the homeland. However, it is known that certain public procedures are not sustainable such as the production of money. From the extractions of the raw materials, to the manufacturing and the disposal of the American currency, we saw that there is a lot of hidden harmful factors that contribute to global warming. Cotton and linen, being the two primary materials in this product, are both expected to be sustainable. However, the process that allows the U.S. Department of Treasury use them for the production of the one-hundred-dollar bill is heavily reliant on one of our most important finite resources, water. Furthermore, the ink used in this high-tech bill, is composed of many unknown chemicals and it is made to be waterproof, causing the deceleration of the biodegradability of the bill. Moreover, the different stages that the materials have to go through to produce the final product is highly machine dependent, generating carbon dioxide emission, polluting our air. Finally, the method in which our government has decided to make usefulness out of our old currency is not effective, leaving a lot of room for improvement. Having observed and analyze the life cycle of the one-hundred-dollar bill, makes me believe that we must find an alternative to our present currency. The production of our paper bills, consumes large amount of our natural resources, contributing to the growth of global warming.

Works Cited

 “Because You Asked: Does My Ink Affect Paper Recycling?” Recyclebank, livegreen.recyclebank.com/because-you-asked-does-my-ink-affect-paper-recycling.

 “Dyes, Pigments and Inks.” American Chemical Society, www.acs.org/content/acs/en/careers/college-to-career/chemistry-careers/dyes-pigments-ink.html.

“Eco-Terms: Biodegradable and Compostable.” Eco-Terms: Biodegradable and Compostable / Green Home Library, www.greenhome.com/blog/eco-terms-biodegradable-and-compostable.

“In Today Society, Money Is the Measure of Success.” Debate.org, www.debate.org/opinions/in-todays-society-is-money-the-measure-of-success.

“Lucky Money Products.” The BEP Store, www.moneyfactorystore.gov/luckymoneyproducts.aspx.

Markets, Roadtoroota.com | Truth Behind. “The Hidden Meanings in the New $100 Bill!” Roadtoroota.com Truth Behind Market Manipulation Bix Weir, 31 Dec. 2021, www.roadtoroota.com/public/261.cfm.

“Paper Currency.” How Products Are Made, www.madehow.com/Volume-3/Paper-Currency.html.

“Plantations.” South Carolina Encyclopedia, www.scencyclopedia.org/sce/entries/plantations/.

“The Risks of Cotton Farming.” Organic Cotton - Risk of Cotton Faming, organiccotton.org/oc/Cotton-general/Impact-of-cotton/Risk-of-cotton-farming.php#environmental.

“The Risks of Cotton Farming.” Organic Cotton - Risk of Cotton Faming, organiccotton.org/oc/Cotton-general/Impact-of-cotton/Risk-of-cotton-farming.php#environmental.

U.S. Bureau of Engraving and Printing - How Money Is Made - Paper and Ink, www.moneyfactory.gov/hmimpaperandink.html.

U.S. Bureau of Engraving and Printing - How Money Is Made - Paper and Ink, www.moneyfactory.gov/hmimpaperandink.html.

“US5059245A - Ink Incorporating Optically Variable Thin Film Flakes.” Google Patents, Google, patents.google.com/patent/US5059245.

“UVM Homepage.” The University of Vermont, www.uvm.edu/.

WHAT'S THAT STUFF? - Ink, pubs.acs.org/cen/whatstuff/stuff/7646scit2.html.

“Where Does Old Money Go?” Wonderopolis, wonderopolis.org/wonder/where-does-old-money-go.

www.epa.gov/air-pollution-transportation/carbon-pollution-transportation.