3D PrintingLessons

What is support in 3D printing?

Lâm Chí Tâm · August 15, 2026

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3D printing makes objects with very complex shapes. That doesn't make it perfect — it has its own weaknesses, and today is about one of them: support.

A layer needs the layer below

A hand lifting a print bed full of small brown parts out of a Bambu Lab printer — 3D printing handles very complex shapes.

Last time: 3D printing builds a shape by adding material, the lower layer and then the one above, layer by layer. Which means every layer needs the one below it to sit on. So what happens when an object has a part that hangs in the air, with no layer underneath?

A green printed block whose overhang has collapsed into tangled strands — An overhang with nothing under it: the plastic falls into strands.

The way to print overhangs is to print props at the same time as the object. In 3D printing those props are called support, and they are what makes so many complex shapes printable that other methods would take a long time over.

The slicer showing green props under the overhanging part — Support in the slicer.

A white print with tree-shaped support beneath it — Tree support.

But support is not a perfect answer. Printing it costs more material and more time, and the surface that touched the support is usually not clean.

Me in the workshop with “Mất nhựa — Mất thời gian” beside an orange part — Support: material and time.

The problem: a floor tile

That was exactly my problem printing a floor tile for a furniture business. Their need was simple: before paying hundreds of millions of đồng for a production mould, they wanted a few samples to judge the design. So they came to me.

Photos of black and grey plastic floor tiles on a table — Modular floor tiles.

Look at the design: both faces carry pins — one side to stand on the ground, the other to take the wooden boards. Which means, printed, 95 % of this part hangs in the air. Without support it cannot be printed at all. Add support, and the slicer's simulation shows the time and the wasted material climbing to absurd numbers.

A CAD model of the tile with its diagonal lattice and pins — Pins on both faces.

The slicer with the tile buried in green support — With support: time and material shoot up.

The answer: print the pins separately

Take every pin off one face and print them on their own. That gives a flat face to put down on the bed, and no support. But on its own that isn't enough: after printing, fitting the pins in the right places would be very hard, and if they are off-centre the boards won't go on. So I cut a locating hole at every pin position. After printing, they simply push in.

A brown CAD model of the tile with the pins removed from one face — A flat face to put down on the bed.

A close-up of a pre-cut hole at a pin position on the model — A locating hole at every pin.

A Bambu Lab printer printing the red pins — Pins, printed on their own.

A hand pushing a red pin into the grey tile — Push them in.

That saved material, saved print time, and kept the quality as high as it could be.

The grey tile with all its red pins, on a cutting mat — The tile, all pins in, no support.

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