When redesigning parts previously manufactured by using other processes, using thinner walls and rib reinforcement can reduce weight by eliminating heavy masses.

In the example above, the boss shown in (1) is bad due to the heavy mass of material in the walls, which will lead to porosity and increase cycle times. The boss shown in (2) is better, with a more uniform wall thickness and the heavy walls replaced by ribs. The boss shown in (3) is also good and requires no movable cores or core slides.