Osmo products provide best results when applied directly onto natural wood.
Applying directly over other oil-based finishes is not recommended since the surface may not be able to absorb as much of the oil as expected, or applying directly over older microporous finishes may provide inconsistent results.
We recommend to clean or slightly sand old microporous finishes, whilst surfaces treated with film coatings such as varnishes or lacquers must be sanded before application.
