Wall Order - Inner First

This setting determines which walls of a perimeter are printed first - outer or inner.

When enabled, perimeters will be printed from the innermost wall to the outermost wall. If this feature is disabled, the perimeter will be printed from outer wall to inner wall.

Wall ordering from inner most to outer.

When to use Outer wall first

This feature can help with dimensional accuracy since the outer perimeter is laid down first and any extra filament extruded when printing following perimeters is pressed back away from the outer wall. On the other hand, the surface may be slightly less smooth.

When to use Inner wall first

Printing the outer wall first is generally worse for overhang. The outer wall is further removed from the previous layer than the inner wall. When printing the outer wall first, the outer wall has nothing yet to grab onto. When the inner wall is printed first, the outer wall can sideways attach to the outer wall.

Also, when you have infill being printed before walls, it is better to print inner wall first, as it creates a continuous part, moving from inner wall to outer wall.