The Juicy Science of Mental Marker FX

In a previous article, “Magic Formula Generates New Tricks,” I divulged my methods for coming up with new magic plots, or “problems to solve,” as I like to call them.

In this article, I will reveal the science behind my latest release, “Mental Marker FX Juice 3-N-ONE,” from initial concept to mass production quality control.

Before we begin, I would like to point out that there are two types of people who read this blog: science & tech fans and magicians. My theory is these two should get together more often, but there are these foolish notions of language and interest barriers. I attempt to write my articles in such away that it satisfies a range of readers, and is easily understood by either discipline.

I have heard, “science is magic grown up.” I prefer to think, “Science is magic focused.” With that in mind, let’s focus on the juicy science behind Mental Marker FX in a way that entertains both groups…


The original: Mental Marker Special Effects Pen, fine point.

Mental Marker FX Juice is the sequel to another utility I released a few years ago, “Mental Marker Special Effects Pen“: a fine point marker—the first of its kind—for magicians who want to perform traditional Ash on Arm routines—plus a variety of new possibilities—impromptu.

Ash on Arm is one of the oldest magic tricks still performed today. In the most popular version, the magician has a card selected,lights it on fire, and then rubs the ash on his arm, revealing the name of the card. In another version, the spectator thinks of a name, writes it on a piece of paper, and burns the paper. The magician rubs the ash on his arm, revealing the name in ghostly printing across his skin.

Originally, magicians used a common, everyday item to reveal the card or name in the ash (I won’t expose it here). In my opinion, the traditional method, while legendary, had several drawbacks. I felt a little research and experimentation with one of my favorite aggregate of surfactant molecules, known as a “micelle,” would revolutionize the trick.

Cross sections of micelles. The cylindrical structures on the outside of the examples are hydrophilic and the inside wavy lines are lipophilic.

Micelles are nature’s chemical negotiators. They are a collection of molecules that allow immiscible (incapable of mixing) compounds to get together and play.

Picture a ball of tiny particles. The outside of the ball is composed of hydrophilic molecules, meaning they are attracted to water, and the inside contains lipophilic molecules, attracted to oils. It is well-known oil and water do not mix, but when dispersed evenly through a liquid colloid containing micelles, the impossible happens. The two substances combine.And in some instances, their intimacy goes a bit further; the immiscible substances attract to one another. In a nutshell, that’s how Ash on Arm works. That’s the secret.

Chemically speaking, Mental Marker FX Juice is the common isomer of propanol united with polyol in an emulsifier used to bond a [36-letter] surfactant with oxygen. This mixture is “sticky” to the molecules in ash (and many other substances, such as chalk dust, cosmetics, and just about any fine powder), while still attracted to one’s oily skin.


In the past, my fellow developers have produced some amazing methods for Ash on Arm with pen-type writing utensils. While excellent products, they were not true pens or markers. Mostly, they were [amorphous] solids in the shape of a crayon. There is nothing wrong with those methods—they fulfill the requirements of the original trick as it first appeared in Hocus Pocus by John White in the 1670’s—but the advantages to a liquid solution are significant.

  • An ink, or Juice, capable of producing the same results as the original method could be focused through a narrow nib, empowering the magician with fine-line attention to detail (perfect for an illusion of growing old, revealing a creepy joker face, appearing tattoos, etc).
  • Juice drawn on the skin would last longer—in both the number of performances and throughout the day after application—providing a significant value to customers (one bottle might last 300 performances in a Mental Marker Special Effects Pen, and the Juice could be applied many hours before performance when necessary).
  • Juice could be used during performance, easily applied while the magician is in front of the audience. It dries quickly and is apt to leave less shine than alternatives. Magicians can secretly palm and apply the Juice from both the Mental Marker Special Effects Pen and 3-N-ONE applicator bottle. Since it is a liquid, magicians can inject Juice into self-inking rubber stamps. Magicians order “stamp versions” of their business cards and use Juice to produce it on a blank business card or on the spectator’s arm, either secretly, or under the guise the stamp is out of ink. Likewise, Juice is compatible with any Ash on Arm stamp-style trick already on the market and with regular rubber stamps found in mainstream stores and hobby shops.
  • Juice, well-researched and highly innovative, is not limited to skin. Other surfaces are now subject to the Ash on Arm concept (Thank You micelles). Imagine a ghostly card on window; your breath or dust from the window sill reveals the chosen card. One can draw a hand on a piece of paper with regular ink, rub ash on the hand and a chosen card appears within the drawing. There are hundreds of possibilities to explore.

Typically, once an idea like this digs itself into my brain, it won’t leave me alone until it’s tested out of feasibility or produced. So in the back of my mind, I quietly formulated about a dozen possible solutions over the course of three years.

Sheets of paper burned in a jar to produce a consistent ash for testing.

My breakthrough was during the early development of our Manip-Quick line (now Manip-Quick Manipulotion Spray is a bestseller). I learned firsthand what saponification is—how fats are hydrolyzed into fatty acids and then mixed with an alkaline solution. I wanted to understand every aspect. I started making the compounds from scratch, literally burning wood and leaching my own lye for quality control. Trial and error until I learned the process inside and out (today, we buy the raw goods made to spec to ensure consistency).

One of my experiments resulted in a byproduct that I instantly recognized as the world’s best Ash on Arm method in liquid form. The process that created it was completely unnecessary. I could produce large amounts of this new compound without the wood pits or chemicals. In fact, the process had nothing to do with saponification and was, as they say, a happy accident.


Prototype Phase: Comparing sample batches of Juice. The best of the best.

I had a successful formula. I knew it would work. It needed tweaked and the proper proportions finalized, but the overall ingredients were known.

This is where the fun begins. Colleagues who have worked with me on a project know I start on the opposite end of the spectrum and work my way back to the original hypothesis. I’ll say, “Okay, we have a possible solution. This is probably how we’ll make this stuff. Now, let’s find a hundred other ways. Maybe one of them will be better.”I test everything else that might work until I arrive at the best possible method. If I ultimately return to the place where I began, then so be it. It isn’t a waste. I want my customers to have a well-researched product. And I never stop looking. If I find a better Juice mixture five years from now, I will change the formula.

Each letter of “TEST” is a different version of Juice.

In addition to testing the mixtures myself, I also poll a focus group. If you are friends with me on Facebook, there is a good chance I have asked for your feedback on a product or two (or ten). I poll about 1000 people per year, sometimes in focus groups of 20, other times 200. Social media has a role to play in research, development, and quality control.


Most of the items we manufacture—over 100 now—require more than one step to complete. We don’t just repurpose off-the-shelf products or assemble loose parts. We actually take raw goods and transform them into brand-new products. Some of those items have in excess of twenty separate manufacturing steps. And since the market is small, the only way I can ensure a quality product is to install quality control checkpoints between steps.

One of our products is a stainless steel tube, heavily reworked with tools thin as a human hair. I construct it in such a way the step after the step before is impossible if certain benchmarks are not met. It is my way of looking over my own shoulder. When I finish my work, I know the product meets or exceeds my standards or it wouldn’t be this far along in the manufacturing process.

The first bottle of Mental Marker FX Juice. I used this bottle to performance-test the finished product.

With a product such as Mental Marker FX Juice, the exact measurement of ingredients is vital. And when dealing with these particular compounds, evaporation, expansion from temperature changes, and even the difference between suppliers can influence the final product, tipping the scale of quality without notice.

To overcome these woes, we practice small batch production, much like premium distilleries. I will make a small batch of Juice, enough for twenty retail units, test it, and get it to what I consider optimal working condition. Then I do this three more times. Once they are all good to go, we mix them together and re-test. If the Juice passes my benchmarks, then it gets packaged and shipped to magicians and distributors. This is the same process Vodka distilleries use to reach 95-100% purity in their spirits (though we don’t let product age on the shelves).


Many a good magic trick goes bad in shipping. Some of the items we sell cannot be shipped bottled in an oxygen environment. Those items are packaged with an inert alternative. The Mental Marker FX Juice bottle had to go through rigorous testing before we could announce the product worldwide.

Empty bottles ready to fill with Mental Marker FX Juice.

The first step was simply to see if the diluted alcohol in the mixture melted the plastic bottle. The next step was to see if the bottle leaked with weights sitting on it (I use an anvil). And the last step was to ensure the bottle could withstand the molecular structure of fluid expansion and contraction with the changes in altitude during flight.

The first two steps are tested in-house (literally, I take these home with me to watch them over several nights and in different temperatures), and the last step is tested with a bit math, some common sense, and then we ship a sample just to see if our calculations were accurate [and realistic].

Mental Marker FX Juice ready to ship!

Small-market manufacturers often overlook altitude’s effect on product. We have to take into account every aspect of transport. Sometimes, a change in altitude forces oxygen into the packaging, drying the contents (glues for instance), other times it sucks the oxygen out, causing the container to leak. We test all of our products for altitude damage, slowly tweaking our formulas until they can arrive in good order, regardless of the destination.

When we are all done, I design a front cover, write a product description, and announce it on The Magic Depot website with a special introductory offer. After about two weeks, wholesale orders start to come in, and we ship those in bulk. My wife and I release about a dozen new products a year in this fashion. And with every one, you can imagine the science behind the magic.


Would you like to see the Mental Marker FX Juice 3-N-ONE for yourself?

Get two broad-stroke bottles for only $19.95 plus shipping. For a limited time only, get a Mental Marker Special Effects Fine Point Pen with your order, FREE!

Click HERE to purchase from The Magic Depot, or place a quick order HERE via PayPal!

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  • Wilhelm Eberhard

    What I like about the liquid product is that it allows artists and calligraphers to load it into their favourite broad edged dip pens. Thus, impressive Arabic, Sanskrit, Hebrew or European calligraphy or decorative designs (such as Celtic knots) can be magically produced.
    For example, you could simply write anything with bad calligraphy, burn it, and then have the spirit of some 16th century monk copy the text for you, just by rubbing the ashes on a paper. You then give the resulting small work of art to the spectator as a souvenir.


      Wilhelm. that is a great idea. FX Juice is perfectly suited for calligraphy and works with calligraphy pens and brushes. Including a monk in the patter adds a lot of mystique. Thanks for sharing!


    Follow Up: This picture shows one of the experiments referenced in my article. The pot contains hydrolyzed fatty acids in an alkaline solution; a process used to make a common, household item.