Pig wrote:
Beggin' your pardon, but two planes that don't intersect are indeed
parallel. First plane is the top face of the board, the second is the
bottom face of the board. If one face of the board is skewed, extended
out enough distance it will intersect with the other face. I don't
understand your comment at all.

Mutt.


also parallel are nested cylinders. and the two faces of cupped or
twisted lumber. a thicknesser won't necessarily take care of either of
those conditions.