Steady

hold a fingertip on the paper.

the pen draws your fingertip at 14x, and it never stops moving

The pen sits at your fingertip's distance from wherever it first landed, multiplied by the gain, so the bold line winding up the paper is a magnified picture of a hand you believe is holding perfectly still. The pale line drawn down the middle of the lane is the same signal at true size, which is what convinced you it was still. Lift off and the pen lifts too and the paper runs blank -- that blank stretch is the control condition, and it is why the ink is evidence rather than decoration. Some of what the pen draws is your own hand and some of it is the touchscreen's reading of a fingertip against glass; the card says so rather than selling the whole line as a tremor.

Concepts: balance, stillness.

An interactive you play with one thumb, on Wundr.