Ferrofluid mist dynamics

Various magnetographic printers have been based on the use of micron-sized ferrofluid droplets to form images on paper. Pulsed laser photography is utilized to follow the droplet motion on ms to s time scales. The results agree with the predictions of a simple model. The only fitted parameter, the drop radius, has a value similar to the values found by other techniques. Results, combined with optical density measurements and the mist density, indicate that mist printing is basically a slow (0.1 to > 1 s) process.