Phyllotactic design is an exploration on the combined use of light and spiral structural patterns. Relying on the tools of parametric design and digital fabrication methods, this proposal sheds light on the mechanisms and effects of luminous objects as well as design aesthetics itself. Using a feedback loop approach, the design process is informed and updated through materiality in order to achieve the desired visual effect. Particular consideration was given to the factors of the overall cost and product feasibility that are closely related to both the production process and the materials. Nonetheless, following a mass customization principle, the design of the shade as well as the selection of materials are relative flexible.