Brodie's GO sheets are prepared, characterized and compared to Hummers’ GO sheets. GO-B membranes are synthesized on polyester substrates using filtration. Permeability reduction of large gas molecules (CH 4 , N 2 and CO 2 ) is more significant compared to permeability reduction of small gas molecules (H 2 and He). Pressure filtration enhances the packing density of GO-B sheets.