want your painting to be too shiny, use a matt varnish rather oilpaintings than a gloss one. Leave your painting to paintings Wholesale dry for several hours, or overnight. Lean it against a wall, face inwards. Dry the painting with another bit of cotton wool. With your fingers, gently remove any cotton fibers that have been caught in the paint. Clean the painting so it's free from dust, dirt, and grease. oil paintings Lay the painting flat, then angel painting dampen a bit of cotton wool with clean water. Paintings For Sale Ensure your painting is completely dry. Allow several months for an oil painting to dry properly. Depending on the thickness of the paint, this could be up to nine months.