I have more ideas for business and products than I have the time, energy or skills to pursue. I am throwing this one out there in the hope that someone else might run with it. You’re welcome.
Idea
1. You zoom into a region of the Mandelbrot set you like the look of. You have an the option to customize the colours.
2. You are shown a visualization of what this would look like on a shirt (front and rear).
3. If you like what you see, you click a button to order the shirt, choose your size and pay. It is then shipped to you.
Pricing
The fact you can design your own shirt and there is a vanishly small probability that anyone else will have the same design, means you can charge a big premium. Perhaps £50/$80 for a long sleeve shirt?
Feasibility
The software side of this business is fairly straightforward. After all the Madelbrot set is based on just z=z^2+c and you wouldn’t have to generate a high resolution image for the preview. But I know nothing about the clothing industry. I have no idea what it would cost to individually print a shirt or what printing technology you would use. Perhaps there are good economic reasons why no-one is already doing this (if they are, they aren’t very good at SEO).
I will be your first customer!
Successful Software 
