Each ribbon is made of a series of straight lines. Before drawing each line I reorient the canvas by a certain angle, sampled from Perlin noise. After drawing I return the canvas to its normal position and then repeat for the next one.

The varying wackiness of the ribbons is the result of changing how quickly we’re moving through the noise field. One of the features of Perlin noise is that it creates smooth transitions between values. That effect is magnified if we “zoom in” (by moving in smaller steps), as I’m doing for the ribbon on the left. The opposite happens if we zoom out, as with the ribbon on the right.