Front Back greyed out!!

[system]

Hello,

under DRAW, the Front Back Menu is greyed out.
Any idea why?

Thanks in advance.
rudi

[marcus_civis]

It becomes active when the Floor button is turned on, and images are loaded onto the grid.

For more info see here:
http://docs.pixologic.com/user-guide/3d-modeling/reference-images/grids/