These plates are 100% H20 resistant and are compatible with aqueous developing solvents. They are less rugged than the plates with organic binder but still provide improved handling and sample application compared to Silica Gel G UNIPLATES and are tough enough to write on with a soft pencil. Hard Layer UNIPLATES with inorganic binder are recommended for all applications including those where visualization occurs involving strong charring procedures or acid sprays or dips.