Cooper Hewitt says...

Angelo Testa was one of the foremost American textile designers of the mid-20th century. In 1945, he became the first graduate of the Institute of Design (formerly the New Bauhaus) in Chicago, where he studied under artist László Moholy-Nagy, architect George Fred Keck, and weaver Marli Ehrman. In 1947, he founded his own firm, Angelo Testa & Co., which remained active until his death in 1984.
Testa did not produce an annual or bi-annual line as other fabric producers did. Instead, once he had put a design into production he would keep filling orders for the design, having new yardage printed as necessary. Some designs were screen printed by his own firm, Angelo Testa & Co., others were produced by Greef, Forster Textiles Mills, Knoll Associates, F. Schumacher & Co., and Cohn-Hall-Marx.
A painter, sculptor, and weaver as well as a designer, Testa was familiar with the work of contemporary abstract artists. He introduced to textile design abstract and non-objective patterns using combinations of thick and thin lines, solid and outlined forms, positive and negative spaces, and clean pure colors. Designing patterns primarily for use within the architecture and interior design trade, his clients included many of the leading producers of mid-century modern furniture and fabrics, including Herman Miller, Knoll Associates, and Jens Risom.