Support structures

Support structures are extra material a slicer adds automatically, or that a designer can add manually, to hold up parts of a model that would otherwise print into thin air. Steep overhangs, bridges spanning a gap, and floating details all need something underneath them while they print, since FDM and resin printers both build upward layer by layer with nothing but the previous layer to rest on.

After printing, supports are meant to be removed, usually by hand for FDM prints or with flush cutters and a hobby knife for cleaner breaks close to the surface. Where supports touch the model, they typically leave a slightly rougher patch that sometimes needs light sanding, which is why designers often try to orient a model to minimize how many surfaces need support in the first place.

Slicers usually offer a choice between full supports everywhere they are technically needed and tree or organic supports that use less material and are often easier to snap off cleanly. A common mistake is leaving default support settings unchanged on a highly detailed model, which can bury delicate features under so much support material that removing it damages the part.