Mappa (Populus, nigra)
Trade Names: Mappa, Mappa Burl , Poplar Burl
Origin: Central and Western Europe.
Range: Mappa Burls are Poplar trees which develop abnormal trunk formations as a result of external influences, i.e. burl growth in the form of widely scattered, little spots in their trunks but not in their roots giving the veneer its burly appearance. The occurrence of Mappa Burl logs suitable for veneer extends from the meadowland along the German Rhine River across to Northern and Southern France.
Uses: As rotary cut wood for high quality face veneer. The wood is not steamed, i.e. rotary cut cold.
Properties: The heartwood is light cream to reddish-light brown. The burl occurs as reddish black spots. The veneer in which these dots are spread as evenly as possible over the surface is highly desired. The Populus nigra is the only species of Poplar which develops these burls.
Machining: The wood is easy to work with all mechanical tools. However, because of the burly growth very sharp tools are needed to prevent a rough surface. Slow feed speeds are to be recommended.
Seasoning: Even when dried very slowly and carefully it is not possible to fully prevent surface checking due to the different directions of shrinkage.