Hyokyung Park, known as Sandoilki (산도일기), spent nine years as an art director in the commercial art world — nicknamed Lemon Art by colleagues for a vivid visual imprint. In April 2025, Sandoilki left the industry to pursue a unique creative voice, coining the term Sajinhwa (寫眞畵, 'Photo-Painting'): layering hand-drawn textures of unconscious emotion onto documentary photographs.
The name Sandoilki (酸度日記, 'Acidity Diary') reflects a pursuit of raw, unprocessed truth.
The artist is also a published writer on Millie's Library (밀리의서재), bringing literary depth to the visual work. The portfolio spans KIA x Wooyo brand campaigns, album concept art for musician Sumbisori, personal art exhibitions like 'Immobility: I Am Not Here' and 'Mobility: I Will Not Vanish', as well as wedding photography and cinematic street portraits. The photographer shoots in natural light and focuses on Bukchon's hanok alleys, Yeonhui-dong's quiet village streets, and Sindang-Euljiro's industrial textures.