This paper investigates Ganoderma lucidum as a living mycelium membrane, exploring its proprieties beyond the scale of individual mycelial pellets and through systematic material processing and characterisation. Mechanical properties and surface differentiation strategies are examined to identify design opportunities where functional performance and aesthetic expression emerge from the material’s living behaviour. Two complementary methods structure the study: tensile testing to quantify mechanical performance and membrane-masking experiments to assess regenerative capacity and qualitative growth behaviour. The results show that living mycelium membranes are thinner than 1 mm and have a Young’s modulus of approximately 1.3–1.5 MPa and tensile strength of 6–10 MPa. Masking experiments demonstrate the potential for selective regrowth and controlled aerial hyphae patterning to create hydrophobic regions. Together, these findings integrate qualitative and quantitative insights to inform applied design contexts, laying the groundwork for advancing fungal living materials toward applied use of engineered living materials (ELMs).