Tuesday, February 4, 2014

$5 of Art in Your Pocket

Paper currency is actually pretty cool if you take a really close look at it.  First of all, the people who do the engraving for the printing press are artists, and second, it makes currency harder to counterfeit.  

So why the five dollar bill? There are things on it that are hidden in plain sight and, if you have good vision, you can see a lot of these features without magnification.  You just have to know where to look.  All images below are from the backside of the five dollar bill.

The color images below were taken with our Leica dissecting microscope.

In the image above you can see President Lincoln sitting in his memorial.  Amazingly, his features have been so finely engraved that he is easily recognizable. I am going to zoom in on his face.  Also notice the "LINCOLN MEMORIAL" text at the bottom of the stairs.

Maybe not so finely engraved after all, but it is pretty cool that just a few lines in the right place allow you to recognize the person.  In this image you can also see the fibers of the paper that make up  the bill.  

Did you realize that the names of the states of the union that are engraved on the actual Lincoln Memorial are also on the five dollar bill?  I love to show this to students who rarely know they are there.

Why zoom in on Texas?  Because I am a native born Texan!

This next one surprised me.  The large 5 on the bottom left hand corner of the bill has a very nice printed pattern and the end of the 5 is marked "USA FIVE".

Not only a pretty pattern, but probably saves a ton of ink when you print millions of these bills.  Of course, by "you" I mean the federal government - not me or you.

In the scanning electron microscope you can see even more detail.  Much of the ink on money shows up really well in the electron microscope.  Some of what I am going to show you here is way beyond the eye's ability to see. 

Here is Texas on the top of the memorial.  You can see that the contact of the ink to the paper is either imperfect or has worn off.  This was a fairly new bill, but it had been used.  I got it in change at a sandwich shop.


The paper fibers are easy to see as is the ink pressed on to the bill.  The X is about 1/2 mm tall.
In this image the paper fibers show up as does the ink.  If you squint, you can still recognize Mr. Lincoln.

Refer to the previous image.  This diagonal line is used to make Mr. Lincoln's hairline.

Here is the same diagonal line magnified 1000x.  You can see the particles that make up the ink and reflect electrons so well in the electron microscope.

I picked a single, pointed ink particle to image.  Its length is 6.27 microns - about twice the length of an E. coli bacterium.  Money is supposed to be very dirty, but I really didn't see any bacteria on it.  Of course, I didn't image the entire bill.

[11,000 x]

This image is of the paper between the ink marks that make up Mr. Lincoln's head.

The large paper fiber in this image is 26 micros wide.  (A micron or micrometer is 1/1,000,000 of a meter.)  The tiny specks all over the place are dirt, dust, and more than likely some cocaine.  It is estimated that 80 to 90% of our currency is contaminated with cocaine.


At the bottom of the steps it says "LINCOLN MEMORIAL".  Notice that in this case, the letters are formed by inking in the background and letting the paper show through.  I thought that was pretty cool.

The "C" in LINCOLN.

I'll admit it - I like money, not only for what it will buy, but because it is a real work of art.  If you haven't already, go ahead and take out a five dollar bill and take a look.

As always, all images produced by the Eastfield College Microscopy Lab are under a Creative Commons License.  You may download, modify, and reproduce them all you like just as long as you  give credit to Eastfield College, Mesquite, TX, and don't sell them.

M. Gans
Microscopy Lab Coordinator


  1. This is so fascinating! I've never noticed the USA Five on the end of the five...granted, I am a poor broke college student I don't get to handle money a lot.

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  3. I am delighted that you liked the images. As the father of a college student I don't see anything larger than a $20 very often. Thanks for taking the time to comment.