Art Forgery 101 wanted to be a painter. Instead, for more than thirty years, I made my living as an art forger.

When I was 18 years old and dead broke, I spent a great deal of time in museums. There were some simple, 16th-century Flemish portraits that I was sure that I could paint. Then one day, I was given an old book someone had found at The Strand about Han van Meegeren, a Dutch art forger from the 1930s and 40s who faked Vermeers. I can do that, I thought.

So I went back to those museums and stared at the painting for hours until they gave up their secrets. Then I spent weeks holed up in my garage, trying to re-create what I’d seen. When I was satisfied with the fruits of my labor, I took the train into New York City, went up to a dealer on West 57th Street, and promptly sold the painting for $800. Eventually, I was selling for $30,000 a pop.

I thought it would be something that I could do to support my own art — making forgeries in the morning, then working on my contemporary art in the afternoon. Quickly, however, forgery went from being something to fall back on to a full-time career.

So how’d I do it? By careful study and by using art dealer’s own prejudices against them.

First, I have always believed that in order to create a good fake, one must start with a genuine love and appreciation of the artist’s work. Creating a fake should be an inspired experience. For me, it begins with reading as much as possible about the life of the artist. I want to know who the artist was: Where and how did he live? What were the events that shaped history at that time? Was the artist dogged by failure or crowned with success? These insights will give me a feel for the personality behind the piece.

Then I spend time studying the work itself. I need to see an uninterrupted evolution of the artist’s work, so I spread out all of an artist’s paintings in order of creation. I get a feel for compositional characteristics and look for common denominators such as backgrounds, color schemes, and subjects that appear in varying ways through his work. Experts are also aware of these patterns, similarities and commonalities in the work of an artist, so it is essential that they are there.

With the aesthetics attended to, it’s time for the forensic effects: How does one make an allegedly antique painting actually look old?

I studied the different trends in material over time. For example, a painting produced in the 19th century on pre-primed canvas will reflect a smoother surface then an 18th-century painting that was painted on canvas with hand-applied gesso. So I concocted a mixture of powdered gypsum from the white cliffs of Dover with a special glue made from rabbit skin that created a surface that mirrored that of the 18th-century canvases.

I also learned how to mimic the wear, damage, style, dust, patina, and cracks that made paintings seem like they had stood the test of time. Essentially, I learned how to duplicate the effects of aging, instead of merely simulating them. I figured out what caused an effect such as cracking, then figured out how to make the same natural effect happen in an accelerated time frame. I studied the external conditions — such as temperature change and humidity — that act as catalysts of the aging of paintings, and I set up environments that reproduced those.

Next is the matter of actually selling the paintings. One must start, of course, with a good fake, but there are many other factors at play in fooling the expert.

The fate of a fake is often determined at the first moment an expert lays eyes on it. Consciously or unconsciously, a multitude of things registers in the experts mind as he or she examines a picture. If something doesn’t look right, suspicion can result and the painting is doomed. It is essential to understand how the expert mind works: the way they look at a painting, what they expect to see, and what they want to see. The forger’s knowledge of the subject must be the equal of the experts.

One of the first things I realized was the importance of framing. A fine frame is to a masterpiece what a Saint Laurent original is to a beautiful girl, so I made sure to have well-done, historically accurate frames (which I often got by buying authentic antique paintings, reusing the frames, and tossing the rest). My second critical revelation was that, for many dealers, their primary appreciation of a painting was its price-tag. As a result, I upped my rates.

I went to great lengths to trick even art dealers who fancied themselves real experts. For instance, it is common for antique paintings that have incurred minor tears to have a number of crude repairs throughout the years. So, for the benefit of any connoisseurs who fancied themselves forensic experts, I added a small patch or two, cut from antique canvas, to the back of the painting. I even went as far as to simulate fly droppings, as those can often accumulate on paintings left unattended and uncovered for long periods of time, and then I passed off those paintings as “flea-market finds.”

Finally, just as important as the painting itself, is the presentation. Not only must the painting be right, but you yourself must be right. Auction house experts are very astute and observant. A correct appearance and plausible story of how one acquired the painting is an essential part of the experience. There are certain kinds of people who walk into auction houses with a painting under their arms, seeking an opinion. It’s important to fit the profile of one of these usual types, such as a person cleaning out a cob-webbed attic after a relative passed away or a picker just in from the last antique show with a find. I most often posed as a polished urbanite considering selling off an inherited asset. A made-up history for the painting was absolutely essential, as you can have the best forgery in the world, but, ultimately, the best way to sell it – in fact, the best way to sell anything — is a really good story.

Then, last of all, perhaps the most important lesson in the field of forgery: Cash the check quickly.

Ken Perenyi is the author of Caveat Emptor: The Secret Life of an American Art Forger.