Sentence:  And like this English master , Mason realizes his subjects in large , simplified masses which , though they seem effortless , are in reality the result of skilled <WSD>design</WSD> born of hard work and a thorough distillation of the natural form that inspired them . 
Meaning of the word marked with <WSD> tags:  the act of working out the form of something (as by making a sketch or outline or plan)