Only you can understand from the context whether this is the correct interpretation, but "Informale" (spelled with or without capital I) is a contemporary art movement of the sixties.

For a definition see:

http://www.artinvest2000.com/arte-informale.html

I have always translated this as informal without the "e" as it is normally written in English. After all it wasn't a specifically Italian phenomenon

http://www.google.com/search?num=100&hl=en&safe=off&q="infor...

The Chelsea Art Museum is also the Home of the Miotte Foundation, which is dedicated to archiving and conserving the oeuvre of Jean Miotte and providing new scholarship and research on L’Informel. Miotte’s extensive collected works are preserved as a legacy for New York, where he has had a studio in SoHo since 1978.

The art of Informel (or Informal Art) had an important role in the European and American post-war art scene, and Miotte was an early proponent. Meaning “formless,” or “away from form,” Informel is related to Abstract Expressionism, but seeks to strip away all reference to representation, and to become a new kind of international language.