After the tumultuous events of the 1970s, Zao Wou-ki returned to the inner reflection and tranquility of Chinese ink brush painting. His oil paintings began to take on some of the characteristics of ink brush painting: carefully controlled variation between light and dark tones, expressive evocation of particular moods, and refined elegance. What was first a gradual transformation of Zao's style had by the 1980s become a complete transformation. The structure of his paintings became less focused and more dispersed, less outward-oriented and more inward-looking. His paintings now had a sense of freedom, alternating between the ethereal and the down-to-earth at the artist's whim. Zao abandoned the heavy, powerful brushstrokes he had used in the past and the lofty, intense sense of movement; instead of the finely detailed technique of earlier paintings, his new work was characterized by soft, flowing traces. Around 1980, Zao's art took on an aspect that was at the same time wild and calm. These paintings seemed to embody a boundless, awe-inspiring universe, with a poetic power to entrance the soul of the viewer. In these works, Zao Wou-ki entered a new world of freedom in which his creativity could soar untrammeled.

The Taiwanese poet and artist Chu Ko gave the following appraisal of Zao Wou-ki's oil paintings with their ink brush painting-like style: "Each of his works has a principal shade and the principal shade of each piece is never a primary color. Instead, similar colors are set off by contrast in different arrangements. Though the works are oil paintings, they are smeared with rich and interesting colors. Oil paints are tempered to form the neutral tone of watercolors – a feat which western artists find difficult to achieve. The implication of the colors reflects the three popular notions of Oriental watercolor philosophy; nevertheless, the rich tones cannot be attained by real watercolors." (Chu Ko, "Truth of Nature", in Yuan Dexing (ed.), Album of Zao Wou-ki, Prinkmaker Gallery exhibition catalogue, Taipei: Yuancheng Publishing Co., 1980)

Without the inspiration provided by traditional Chinese ink brush painting techniques, Zao Wou-ki could never have produced the inspired, exalted oil paintings of his later years. His paintings embody the Chinese way of exploring the inner universe – a meditative, contemplative approach to art. The transformation in Zao's work attracted the attention of the noted New York art dealer Pierre Matisse (1900 – 1989), the son of the artist Henri Matisse. After establishing his own gallery in New York in 1931, Pierre Matisse successfully promoted the art of European artists such as Joan Miró, Marc Chagall, Alberto Giacometti and Jean Dubuffet in North America. Matisse began collaborating with Zao Wou-ki in 1980, and over the years arranged three solo exhibitions for Zao in New York. In 1981, Zao also received official recognition from the French government, with the holding of an exhibition of his paintings at the Grand Palais, followed by a touring exhibition; Zao Wou-ki's artistic career had been comprehensively validated.

In his praise for Zao Wou-ki's work from the 1980s, leading U.S. art historian Jonathan Hay has suggested that Zao seemed almost to have entered a kind of "state of grace." Zao strove to make his paintings as spare and streamlined as possible, seeking to create a greater sense of space. This feeling of space was something that Zao was constantly working to achieve; he aimed to find the spiritual vision concealed within the canvas. In his mature period, Zao Wou-ki created a whole series of entrancing, poetic works.

"29.2.80", this expressive masterpiece that Zao Wou-ki completed in the spring of 1980, is an outstanding example of his later work. The painting demonstrates the artist's sensitivity to – and master of – color, while at the same time embodying the essence of traditional Chinese landscape painting. Although it is an abstract work, Zao Wou-ki has used his skillful brushwork and warm tones to lead the viewer deep into the misty, forested mountains, where we stand entranced by the endless variation in the pattern of the mist and clouds. Zao excelled at the playful integration of abstract and realist, and this, together with his mastery of both Western and Eastern styles, enables him to move freely between abstract and realist, creating synergy between them; his paintings are simultaneously realist and abstract, Chinese and Western. This entire work constitutes an exploration of the inner vision; it is a painting rich in emotional force, but is not mystical in the negative sense. In this picture, through his effective control of light and color, Zao Wou-ki strives to achieve the sense of harmony between heaven and earth that was the goal of the Chinese literati painters of the past.