Abstract: Systems and methods of additively manufacturing leak resistant objects are disclosed. Provided herein are methods of forming objects having walls and/or surfaces that are resistant to leaks. Objects disclosed are formed from or manufactured from compositions, including metals, polymers, and combinations thereof. Objects provided herein are made from methods of forming individual shells, forming of series shells, and layer-by-layer forming of objects. Further disclosed are methods of interconnecting shells, layers, and processes for transitioning therebetween the shells and layers.