Black Gridded, Sterile. Whatman black and green mixed ester membranes are composed of cellulose acetate (-20%) and cellulose nitrate (-80%). These membranes are characterized by a smoother and more uniform surface than pure nitrocellulose filters.
Reeve Angel Brand Filter Papers Grade 202, 11 cm. Provides minimum filtration speed of coarse particles. The surfaced is creped, hence it has a greater true surface area than smooth surface filter paper of the same diameter.