It started few years ago when I wanted to build some device it started with a breadboard then it was time to shrink it

This thing is a giant leap, although it was really hard to work with this material 

Now I tried building my own using a nail polish/marker and some chemical to etch the copper away 

The result was ok but I couldn't reproduce easily and the main problem was the size of wire which with this 'technology' was about 2mm.