In the late 1980s and 1990s, Kapoor was acclaimed for his explorations of matter and non-matter, specifically evoking the void in both free-standing sculptural works and ambitious installations. Many of his sculptures seem to recede into the distance, disappear into the ground or distort the space around them. In 1987, he began working in stone. His later stone works are made of solid, quarried stone, many of which have carved apertures and cavities, often alluding to, and playing with dualities (earth-sky, matter-spirit, lightness-darkness, visible-invisible, conscious-unconscious, male-female, and body-mind). "In the end, I’m talking about myself. And thinking about making nothing, which I see as a void. But then that’s something, even though it really is nothing."