Self-sufficient and self-contained, Untitled (Progression) marks Judd's reprisal of one of his most successful and elegant works, filled with the crisp precision and eloquence that marked so many of his works. Judd sought to separate art from illusion, or representation, and it was with this in mind that he created his so-called 'Minimalist' works. Untitled (Progression) has been created according to a precise and eloquently simple mathematical progression, each segment and void increasing and decreasing proportionally and respectively. This work does not refer to the world around it, is not dependant on outside factors, but stands alone, an entity and an artwork in its own right, obeying its own strict internal logic and therefore eschewing any subjective content that Judd himself may have been tempted to create. For Judd's art is not about self-expression, which he came to see to some extent, despite his respect for many Abstract Expressionists, as self-indulgence. Instead, it tries to capture something simple, universal and true.
Hanging on the wall, Untitled (Progression) states its mathematical formula in three dimensions horizontally. In this way, it occupies the space traditionally reserved for pictures and reliefs. However, Untitled (Progression) is neither. It is a sculpture, an object in its own right, and its horizontality is itself a statement, an assertion, about the state of art in the modern world. By using mathematical formulae or set measurements as the basis for his works, Judd managed to reduce his own emotional interference, and the viewer's interpretative interference. However, as has been discussed more and more in recent years, Judd was also interested in colour. Unlike the mathematics upon which Untitled (Progression) is based, color is not a constant in the world, or even in our own minds, and it was this shifting quality that interested him. Judd's use of color is in part arbitrary: it is the infinitely inconstant capacity for color to evoke infinite reactions and emotions in people that provided a constant, in the artist's mind as rigorous and immovable as the formula of the progression. However, Judd could not wholly suppress his own natural colourist impulse: the absorbing elegance of Untitled (Progression), reinforced in its imperial, even spiritual, purple, betrays his instinctive and engaging understanding of color.