High-permeance, molecular-sieving, nanoporous single-layer graphene (NSLG) membranes are highly promising for gas separation. However, the formation of cracks during transfer NSLG to a low-cost porous support is difficult avoid. These detrimental selectivity, and therefore, make scale-up gas-sieving challenging. To mitigate crack on macroporous supports, herein, we demonstrate mechanical reinfo...