Among other obscure and unrelated interests I am an avid coin collector when my finances permit. As such I'm inherently interested in the aesthetic qualities of money. Although it reeks mildly of jingoism, I happen to think that the U.S. has the most attractive banknotes on the planet. I'll concede how badly we're outclassed, particularly by the Chinese and Australians, in terms of coinage. But American money, if you'll overlook a tautology for a moment, just looks like money should look. There's something classic and timeless about those bland green bills.

Sadly the challenges of modern technology necessitate that we make our money progressively uglier in the name of security and anti-counterfeiting measures. The $50 and $10 successfully incorporate red and blue without looking too ridiculous, but the new $20 and $5 bills bow to the global trend of plastering purple and other garish colors on currency. Soon I am afraid the "greenback" is going to end up looking like the monstrosities becoming regrettably common around the world these days:

To me, this does not look like money. The first ($50 Australian) looks like a Disney gift certificate. The second (Lebanese) looks like an IHOP place mat. Nevertheless the sad reality is that banks are hard pressed to stay a step ahead of the technology available to counterfeiters. Some countries, Australia included, have abandoned paper and are using plastic polymer banknotes. I've had my hands on a few and it's…different. Weird. But given its advantages in durability and security I expect that they'll be replacing most paper currency in the next decade or two.

Another vaguely creepy invention slowly working its way into banknotes is a nanotechnology called Motion which implants a ribbon with 650,000 tiny lenses that create the impression of movement. Sweden's 1000 Kronor is the first to use it and it is reportedly being adopted in the upcoming revision of the $100 Ben Franklin. It sounds like a plain old hologram, but I've held one of these and it's mind-blowing.

It is costly technology but has to be goddamn close to impossible to copy. Then again we've said that about a lot of security features – embedded threads, for example – yet the world is flooded with $100 "supernote" counterfeits so flawless that even the Secret Service can't reliably detect them. Because the Treasury argues that it would take nation-sized resources to produce counterfeits this good, the government has long accused North Korea of being the source of Supernotes. There's quite a bit of evidence to support that, although it is questionable that a technologically backward sinkhole like that could produce such good work.

For all the bells, whistles, and Sesame Street colors we're adding to money, though, the hardest parts of American currency to replicate rely on technology that is over 200 years old. The paper, produced exclusively for the Treasury Department since 1805 by Crane & Co. of Massachusetts, is made of linen and cotton (no wood pulp involved) and is very tough to replicate. Second, the bills are printed with an ancient printing technique called intaglio. It leaves raised ink on the bills, making bills produced with common printing techniques smooth and easy to spot. But as hard as these features are to replicate, someone out there is doing it. North Korea? Russian mafia? Iran? It doesn't matter. Whoever it is, we'll keep making changes and hope they can't keep up.

I'll console myself by stockpiling a few greenbacks before we go all plastic and day-glo, and I'll try not to prejudge the concessions to new technology. I'll find a way to love the next generation of banknotes – as long as Rep. Patrick McHenry doesn't get his way and bump Grant from the $50 in favor of…oh, go ahead and guess.