In Zen Buddhism, it is believed that all things come from Śūnyatā (emptiness or void). For Cheung, “void” is not a concept, but something that can be understood through experience. The essence of void and the relationships between subjects are crucial elements in understanding Cheung’s work. His work explores the relationship between space and presence, employing chiaroscuro and hues in a minimal setting, to reflect on the interactions between one's self and environment.

禪學裡的概念相信：「萬物皆從『空』（Śūnyatā）裡來。」——萬物皆能成空（停頓），亦能藉以空（開始）而叢生。他的創作風格以簡約見稱，其作品佈局都以「空間」、「光影」和「純色」這三者有關，從中反映自身在生活裡與不同事物之間的互動。張施烈相信「空」不意旨一種概念，而是需要了解箇中的體驗。若要了解張施烈的創作和其核心價值，「空性」和「關係」的美學是至為重要。