Graduating with a BFA from Seoul's Hongik University in 1959, Ha began experimenting with geometric abstractions in the early stages of his career. White Paper for Urban Planning (1967) from the 'Urban Planning' series, for example, depicts angular shapes composed of straight lines and monochromatic gradients that echo decorative patterns found in traditional Korean architecture. In an interview with Ocula Magazine in 2017, the artist reflected that the series was inspired by the urban development that was then going on in Seoul, which led him to search for ways of creating 'modern works while incorporating something of my culture that has always been there'.

Ha's artworks are also marked by his use of inexpensive and quotidian materials, a trait he shared with many of his contemporaries working in post-War Korea. As the artist reflected in his interview with Ocula Magazine, he could not afford to produce large scales of only one type of work and wished to investigate the full range of materials available around him. In the installation Relationship 72-11 (1972), for example, Ha strung rope between two walls of a gallery and placed an upright wooden beam on top. He also incorporated barbed wire into his paintings, arranging it horizontally in Untitled 72-C (1972) or in a grid pattern in Work 73-15 (B) (1973). Burlap sack, which was dispatched by the United States for relief goods during and after the war in Korea, became one of his favoured canvases as well.

Around the same time as he was experimenting with burlap sacks and barbed wire, Ha began working with a method known as bae-ap-bub, which involves pushing paint through the back of the canvas. Though simple, this method allows for countless variations depending on the size of the pores in the fabric and the pressure with which the paint is applied. In his 'Conjunction' series (c 1970s–ongoing), Ha employs bae-ap-bub to create diverse surfaces that range from the vertical columns of light and darker shades of oil paint in Conjunction 79-11 (1979) to short, vertical strokes of white in Conjunction 05-171 (2005). Others, such as Conjunction 16-321 (2016), depict an array of short, angular marks that resemble the vowels of hangul (the Korean alphabet). Many 'Conjunction' paintings also foster a sense of dimensionality where the edges of paint congeal, as can be seen in Conjunction 14-136 (2014) and Conjunction 18-07 (2018), among others.

In his interview with Ocula Magazine, Ha explained that the word 'conjunction' 'is really the essence of my work: the conjunction between the materials—oil paint and hemp cloth—and my spirit and performance.' This concern with the intersection between the act of painting and the physicality of the materials that go into it is deeply in alignment with the philosophies of the Dansaekhwa artists at large.

Ha exhibits internationally, including at the National Museum of Modern and Contemporary Art, Gwacheon (2012); Gyeongnam Art Museum, Changwon (2004); and Fondazione Mudima, Milan (2003), among others. In 2015, his work featured in the exhibition Dansaekhwa, a Collateral Event of the 56^th Venice Biennale. Widely recognised for his contribution to contemporary art in Korea, Ha served as the chairman of Korean Avant-Garde Association between 1969 and 1974, commissioner and advisor to the inaugural Gwangju Biennale in 1995, and the director of Seoul Museum of Art from 2001 to 2006.

Sherry Paik | Ocula | 2019