The large printed circle acts as a distance sensor allowing you to control the pitch of the audio while the three printed circles along the bottom act as buttons allowing you to control the frequency.
This instructable will show you not only how to create the flyer with conductive ink, but also how to create the hardware and cable.
Below is a video of it in action (this is also going through some fun audio effects on stage)...
Step 1: Create the Flyer
1. There must be four separate sections of conductive ink. One acts as a distance sensor and will eventually control the pitch of the audio. This part of the artwork should ideally be as large as possible as the larger it is, the more sensitivity the sensor will have. The other three sections will act as buttons that will allow us to control the frequency of the audio and don't need to be as large. It is important that none of these sections touch each other.
2. The four sections should have traces (a painted/printed line no thinner than 1mm) taking them to the edge of the paper terminating in a 5mm x 5mm square of ink. These squares of ink should be side by side with a 5mm gap in-between. This is clearly shown in the image of my print on the bottom right hand corner. This print was A5 in size.
When it comes to creating your artwork it doesn't really matter how you do it, but the two easiest ways are to either paint by hand or to screen print. Screen printing means that not only do you get a high quality print, but you can print as many as you like easily.
Painting is easy, just remember to follow the constraints above.
Screen printing with Bare Conductive is a little trickier as it tends to dry quickly in the screen. To get around this I found it best to dilute Bare Conductive with roughly 1 part water 10 parts Bare Conductive. This makes the whole process a hell of a lot less stressful. When it comes to selecting a good screen for the ink, I recommend using a textiles screen with a mesh of around 90t.