[From the linked site:]
As with many pioneer animators, Mary Ellen Bute is hardly known today, primarily because her films are not easily available in good prints. This was not always true. During a 25-year period, from 1934 until about 1959, the 11 abstract films she made played in regular movie theaters around the country, usually as the short with a first-run prestige feature, such as Mary of Scotland, The Barretts of Wimpole Street, or Hans Christian Andersen--which means that millions saw her work, many more than most other experimental animators. [....]