Supramolecular organic frameworks (SOFs) represent a class of microporous solids with excellent light-gas selectivity, as well as good solubility/dispersibility in common organic solvents. We created new mixed-matrix membrane (MMM) materials by blending the microporous, solid supramolecular organic framework material, pillar[5] arene (P5-SOF) with the commercial polymer, Matrimid-5218 (TM), and tested their light gas separation performance. These purely organic MMM materials were found to have very high (light gas/CH4) selectivity values (CO2/CH4: 180, N-2/CH4: 6.5, and H-2/CH4: 600), illustrating that they have promise as membranes for high-purity CH4 separations.