Also in the 1990s, Halley started to produce site-specific installations for museums, galleries, and public spaces that would interact with the surrounding architecture. His installations mix imagery and media such as painting, fiberglass relief sculpture, wall-size flowcharts, and digitally generated wallpaper. Halley created his first site-specific installation at the Dallas Museum of Art; this installation included paintings, silkscreen prints, wallpaper, and murals of flow charts and other images. The flow charts had entered Halley's lexicon around 1994 as both elements of paintings and as independent works; they are "readymade models from textbooks and manuals and other such sources of hierarchies or processes of various kinds, from business hierarchies and divisions of labor to psychological and sociological theories of human relationships and behavior to commodity-production processes." Describing his new approach, specifically the implementation of flow charts on the walls, Halley said: When I was planning to include them charts in my Dallas show some people said that it would be too didactic to put a flow chart next to a painting to show the connections between them. But I use flow charts that are as opaque as possible; in other words there is no specific information. In fact, they make no sense without their captions. What happened in Dallas was that viewers first looked at the flowcharts, then they looked at the paintings. I think it was a way of giving the average person information about the paintings.