Now that you've built it , in order to paint with your Light Paintbrush you'll need a dark place and a camera or smartphone with "bulb" or long exposure mode.
On a camera, look for a "B" on the dial or check the far end of the shutter values. Bulb may require a held shutter, so it can be convenient to use a shutter in the 10-to-30 second range (notated as 10", 20", 30" and so on), or a remote trigger.
For smartphones there are many apps available -- just search for "long exposure" or "light trails" in the app store of your choice.
Now, head to a darkened room or outdoors at night. Set your camera or smartphone on a table or tripod, put it in long exposure mode with a small aperture to keep the scene fairly dark, and press the shutter.
Turn on your Circuit Playground Light Paintbrush, set the brightness knob to a medium setting, and move the Light Paintbrush in some circles and arcs. When you're done, press the camera shutter again and check your photo.
It may take some tuning to get the brightness and focus just right -- it's very helpful to have an assistant -- but once you do you'll see beautiful streaks of light with colors changing depending on the rotation arc of your arm or how you twist your wrist.
This image was a single streak during a five second exposure.
For these jellyfish-like images, the brightness knob was twisted on and off while moving and twisting the brush.
Less can be more.
More can also be more.
Here I illuminated my face briefly as well by pointing the Light Paintbrush at myself.
An external flash (or bright light turned on and off briefly) can help add your subject to the photograph without blurring.
Enjoy creating art with your Circuit Playground Light Paintbrush!