Page 2 - Varnish
Varnish protects the painting from dirt and dust and evens out the painting's final appearance, making it all equally glossy or matt. Over the years, dirt and dust adhere to the varnish, rather than the painting surface. The varnish can be removed and the painting re-varnished to restore its original appearance.
Congo copal is no longer available commercially (at least as it was available in commerce formerly), because the suppliers have long stopped trading due to strife in Africa since the last quarter of the 20th century. Trade of Congo copal was once controlled by the Belgian government, but as this region of Africa gained independence and the demand for copal resins diminished during the last half of the 20th century, the commerce of Congo copal has all but ceased.
