This rectangle shaped canvas (66 1/4 x 16 inches) is almost completely coloured in a black tonality and it is crossed by two thin, unevenly painted blue lines with subtle white reflections.

The painting describes a relationship between colours and shapes in which they both play a crucial role in conveying feelings and meanings to the viewer. This canvas expresses the attempt of unification already present in "Onement I", another famous artwork of the artist.

The whole representation in centred around the concept of "zips", as Barnett Newman frequently called them. A "zip", being almost like a Newman's signature, is a thin, straight vertical line that crosses the canvas and stretches towards the top starting from the ground.

A zip never divides the painting, instead, it tries to merge and unify both sides of it. Unlike in "Onement I", where there was only a single thin line, in "By Twos", as the title may suggest, the artist depicted two zips, creating more spatial order and opening a wider universe of possible interpretations.

Some art critics defined "By Twos" a "moving and quintessential example of Newman's unequalled contribution to the canon of American art during the critical years that followed World War II". His works are enigmatic, mysterious and carry a universal meaning.

The vertical zip theme expressed in this painting frequently returns in other Barnett Newman's artworks like in the "Onement" series, formed by six paintings (Onement I, II, III, IV, V, and VI).

Also in Broken Obelisk (1963 - 1967), a sculpture constituted by a pyramid with an inverted obelisk on its top, the zip motif is still present but this time it is rephrased in three-dimensional space. The sculpture seems to create a giant straight line similar to the ones that the artist painted here.