Butter 3 slices of white and whole wheat bread. Put slices together in
groups of 3, alternating the slices. Have the center slice of one
group white bread, and the center slice of the second group whole wheat
bread. Cut each group in 1/2 inch slices. Put the slices together, alternating
slices from the 2 groups and forming a checkerboard pattern of
brown and white squares. Cut in thin slices. Wrap tightly in slightly
damp cloth. Chill 2 hours.