with generous grants from the Ford Foundation. This period that lasted thirteen years produced a long list of ballet productions in different musical genres, including some abstract designs —such as “Jewels” 1967— is often praised by critics as Karinska's greatest and condemned by others for “garish” colors. For a full list of Balanchine-Karinska collaborations see: The George Balanchine Foundation Online Catalog. Both aging during the 1970s Balanchine and Karinska returned to a fantasy ballet they had begun in the early 1950s —"Birds of America," based on the drawings of John J. Audubon. Elaborate beyond possibility, "Birds of America" was never meant to be materialized; it was a means to keep their attention on life and beauty. Balanchine would spend long sojourns at Karinska's Berkshire home. Karinska would make endless sketches by pasting pieces of fine fabric onto pencil-drawn figures on heavy watercolor paper. They would walk in the woods daily and Balanchine would choreograph by imitating the dances of different birds. (Eye witnesses remarked on the immense effort and skills required to make the complex costumes with the 'extra bounce', in the 1970s, for example resulting in the Cincinnati Ballet gaining knowledge of her 'secret' methods.)[21] In 1983, Balanchine died in April and Karinska died on 18 October; two weeks after her 97th birthday, but six years after a debilitating stroke left her unable to speak or move. The "powder puff" tutu With a large assembly of dancers on stage – as was often preferred by Balanchine—the traditional "pancake" tutu with its stiff wired layer would bob and dip when the dancers' skirts brushed up against one another and this bobbing and dipping would reverberate long after the steps were complete. Karinska solved this problem by devising the "powder puff" tutu, with a shorter skirt made of six or seven layers of gathered net, each layer a half inch longer than the preceding layer. The layers were tacked together for a fluffier, looser appearance than the stiff "pancake" tutu. Because the shorter layers are self-supporting, no wire hoop is needed in the "powder puff" tutu, or the Balanchine-Karinska or American tutu. This tutu design has become standard in ballet companies all over the world since it first appeared in 1950, in the ballet Symphony in C. She also cut the bodice material in a way that was more comfortable for the dancer. Balanchine said, "I attribute to [Karinska] fifty percent