The Berlin Underground Pop-Up Gallery
How a plexiglass backpack, one poster and four hours on the U-Bahn a day gave me my first proof of concept.
In 2016 I was standing at my front door in Berlin, just back from Vietnam, and there was a man. We got talking. It turned out he was a money coach — someone who helps companies out of difficult situations and shows creatives how to actually earn money with what they do.
At the time I was pretty frustrated. I had worked for months on a silk scarf collection — printed in seven colours, well crafted, but it didn’t work. The scarves were too expensive, too complicated, and above all they didn’t feel like me. I found no buyers.
The coach said one sentence that hit home:
“The money is lying on the street. You just have to walk up to it.”
So I went.
Why the U-Bahn?
Approaching people on the street is hard. Whether you want to give something away or just have a question — the first reaction is almost always: “No, leave me alone, no time, not interested.”
On the U-Bahn it’s different. People are sitting. They can’t just walk on. You have two or three minutes in which they listen to you — or at least can’t escape.
And honestly: the cultural competition on the Berlin U-Bahn in 2016 was limited. A few Hit the Road, Jack violinists, a few people selling the homeless newspaper. A real art exhibition? None.
I thought: I’ll do it differently.
The Pop-Up Gallery — setup & routine
November 2016. I built myself a plexiglass display case — a transparent backpack I strapped to my back. Inside: rolled and sleeved posters of my Berlin drawing. I folded one up and put it in my jacket pocket.
Every day the same ritual: buy two short-trip tickets, get on, wait until the train leaves. Then the opener:
“Hello and welcome to the Berlin Underground Pop-Up Gallery!”
At Pop-Up I pulled the folded poster out of my jacket pocket and unfolded it. One metre of Berlin, drawn by me, live on the street, within 30 days. Everything on it that makes Berlin Berlin for me.
I pointed at details — the TV Tower, a street corner, a backyard building — and told people what I had experienced there. No long speech. Maybe two minutes. Then the sentence that changed everything:
“You can buy this poster in my online shop for 24 euros. Or in the store for 25. But because you’re lucky enough to meet the artist in person in this pop-up gallery today — you get it right here, signed, for 10 euros.”
100 euros a day. Every day.
Four hours a day. Two tickets, two hours each. Monday to Sunday. My coach had said: Every day, no exceptions, until it’s in your blood.
I mostly rode the U2, sometimes the U5. On average I had 100 euros in my hand at the end of each day. Cash. Straight from the people who had just seen my work.
Besides the posters I also had postcards with me — for people on the go who said: “No room for such a big picture.” Four postcards for five euros.
I sold about ten posters a day. My rent in Prenzlauer Berg — 600 euros — was suddenly no longer a problem.
“I had never earned that much money with my art before.”
Who buys art on the U-Bahn?
The reactions were mixed — and that made it exciting.
Most people ignored me at first. But once the picture was unfolded, they looked. Some smiled. Some asked questions. Many were simply happy to experience something other than the usual U-Bahn routine.
After a few weeks something happened that I hadn’t expected: Regulars. People who rode at the same time every day recognised me: “Hey, this is the seventh time I’ve seen you — now finally give me one of those posters!”
Not everyone was thrilled. One man — supposedly from the tax office — got terribly upset: “We all go to work normally, and you walk through the U-Bahn selling your stuff!” The street musicians saw me as competition for their turf and tried to drive me out.
The ticket inspectors? No problem. I always had a valid ticket. After a few weeks they knew me and left me completely alone.
Press, TV & the end
On the U5 I met a journalist. He wrote the first article about me — in the Berlin city magazine Tip. After that a TV crew came and filmed me during the pop-up show on the U-Bahn.
🎥 TV feature: Heiner Radau on the U-Bahn
That’s when I knew: time to stop. The BVG wouldn’t be able to ignore that much attention for much longer.
In April 2017, after five months, I ended the Underground Pop-Up Gallery.
What remained — the safety net
But what remained from those five months was more than the money.
It was the first time I really knew: I can live from my art. Not in theory. Not someday. But right now — if I’m willing to go out and do it.
Later I tried to switch to more legal routes. Markets, fairs, galleries. But nothing ever worked as directly as the U-Bahn. Why? Because people had time. Because they couldn’t walk away. And because nobody expects to meet an artist on the U-Bahn who shows them his Berlin.
“If I’m ever broke — all I need is the print file from my cloud, five euros for a ticket and a copy shop. I can’t go under anymore.”
That knowledge gave me a confidence nobody can take away from me.
That’s my safety net. And it holds.
🎯 TIPS: How to find your own proof of concept
This section is for artists who want to know whether their work meets real demand — not as a long-term business model, but as an entry point and reality check.
1. Start small. Really small.
One product. One format. One price. I had exactly one poster and a few postcards. You don’t need more to find out whether someone wants to buy your work.
2. Go where people have time.
The decisive advantage of the U-Bahn wasn’t the setting — it was the forced attention. Where in your city are people stuck with two minutes to spare? Train, bus, ferry, waiting areas.
3. Make an offer people can’t refuse.
€24 online, €25 in the store — or €10 directly, signed, from the artist in person. The price ladder makes buying on the spot the obvious win. And it doesn’t feel like begging, but like an exclusive deal.
4. Be regular. Non-negotiable.
My coach insisted: every day. No exceptions. That’s the only way to become visible, the only way to get regulars — and the only way to take the pressure off yourself, because it becomes routine instead of a test of courage.
5. Don’t sell a product — tell a story.
People didn’t buy “a poster of Berlin”. They bought the poster because they had just heard that I stood on the street for thirty days to draw every line myself. Make your work something people can experience.
6. The test is passed when you feel it.
It was never about selling on the U-Bahn forever. It was about one question: Can I do this? After the first day with €100 in my hand, I knew the answer. Everything else — online shop, Etsy, markets, galleries — came after that. But first came that one moment on the U2 between Eberswalder Straße and Alexanderplatz.
Which unconventional place could be your pop-up gallery?
— Heiner