To hollow a 3D model in a slicer, use the "Hollow" or "Shell" tool—this creates an internal cavity with a thin outer wall (1–3mm typical for 3D printing) to save material and reduce weight while keeping strength.
- Adjust wall thickness: Tweak this setting to balance material use and durability; thinner walls save more but may weaken the model. - Add drainage holes: Use the slicer’s hole or support tools to make small openings—these release trapped air (FDM) or resin (SLA) during printing. - Start simple: For beginners, test basic models first to find the right thickness and avoid fragile spots.