Information:

Walnut has a medium-course but uniform texture and is straight grained.
When quarter sawn, it can produce 'stripe', 'roe', 'wavy' and 'mottle' figures.
However, it is most prized for its 'burr' figure for its great depth and subtlety of pattern.

Burrs or burls are abnormal growths (would-be knots) on the trunk of a tree.
Burr veneers display an attractive pattern of tightly packed bud formations that appear as rings and dots.

The imitation of burr walnut is cost productive, as it is the most expensive and highly prized type of timber veneer.

The painted imitation of timber; 'graining' or 'woodgraining' is taught at various places throughout the world.
See:   http://www.painting-effects.co.uk/workshops.htm