Updated October 17, 2026
Do you need 100% infill to make a 3D printed vase hold water? I designed a simple vase in Autodesk Fusion (formerly Fusion 360), printed it at three infill densities, and filled each version with water for five days. All three held water—but the differences in print time and filament use were substantial.
What You’ll Learn
- How to model a simple flared vase in Fusion.
- How to create a hollow container with a 3 mm wall thickness.
- How 15%, 50%, and 100% infill compare in PrusaSlicer.
- Why infill density alone does not determine whether a print leaks.
- What this five-day test tells us—and where its conclusions stop.
Watch the Workflow — or Read It Step by Step
You can follow this guide in two ways:
- Read the steps below if you want quick written instructions, reference images, and modeling notes.
- Watch the full video at the end of this post to see the workflow in real time — including extra tips, camera angles, and shortcuts that don’t fit neatly into text.
Both formats build on each other.
Reading helps you understand why each step matters, while watching shows how to move faster in Fusion.
Step 1: Create a Component for the Vase
Start a new design in Fusion and create a component called Vase. Make sure it is active before you begin modeling.
Creating a component first keeps the sketches and body organized together. It also makes the vase easier to identify if you later add other parts to the design.
For this experiment, we need just one model. The three test prints will use the same geometry, with the infill settings changed in PrusaSlicer.
Step 2: Sketch a 50 mm Base
Create a new sketch on the top plane.
Draw a circle centered on the origin and give it a 50 mm diameter. Finish the sketch.
This circle defines the outside diameter of the vase’s base. Centering it on the origin gives the model a useful reference for future edits.
The flat circular base also provides a straightforward printing orientation: place it directly on the build plate with the opening facing upward.
Start a sketch on the top plane to define the vase base.
Step 3: Extrude the Vase with a 15° Taper
Select the circular profile and use Extrude with these settings:
- Distance: 50 mm
- Taper angle: 15°
- Operation: New Body
Check the preview to make sure the body widens toward the top. The result should be a flared shape with a smaller base and a wider opening.
The gradual outward slope is useful for 3D printing because each layer extends only slightly beyond the layer below it. This avoids a sudden horizontal overhang and keeps the geometry suitable for printing upright without support.
Extrude the circle 50 mm with a 15° taper to create the flared vase shape.
Step 4: Hollow the Body with a 3 mm Shell
Open the Shell command, select the top face, and set the inside thickness to 3 mm.
Removing the top face creates the opening while retaining a closed bottom. Inspect the model from above to confirm that the cavity is open and the floor remains intact.
The 3 mm thickness defines the material region in the CAD model. PrusaSlicer will then divide that region into perimeters, solid layers, and any remaining infill.
That distinction matters: a 3 mm modeled wall does not automatically mean a 3 mm band of solid printed perimeters. The actual toolpaths depend on the slicer settings.
Also, the closed bottom in Fusion describes the geometry. Whether that bottom prints entirely solid depends on its thickness and the slicer’s solid-layer settings.
Use the Shell tool with a 3 mm wall thickness to hollow out the vase.
Step 5: Save and Export the Model
Save the design and add a short version note, such as “Before Export.”
Export the vase body as an STL file, using millimeters for the export units.
Saving creates a clear checkpoint for the geometry used in the experiment. If you modify the vase later, you can still identify the version behind these results.
Save the Fusion design before exporting it for 3D printing.
Export your STL file via the drop down menu.
Step 6: Import the Vase into PrusaSlicer
In PrusaSlicer, go to File → Import → Import STL and select the exported file.
Position the vase with:
- The flat base on the build plate.
- The opening facing upward.
- A 0.2 mm layer height.
Use ordinary slicing for this test rather than Spiral Vase mode. We want to compare infill inside the modeled wall and base, so a different printing method would change the experiment.
The prints in this test used the same model, material, and modeled shell thickness. The printer was my Prusa i3 MK3S+, which I have been using since 2021.
Import the vase STL file into PrusaSlicer to prepare the test prints.
Step 7: Slice the Vase at 15% Infill
Set the infill density to 15% with the gyroid pattern, then slice the model.
For this version, PrusaSlicer estimated:
- Print time: approximately 2 hours 45 minutes.
- Filament use: just under 10 meters.
Use the layer preview to inspect the walls and base. Infill occupies the space left between perimeter paths and solid surface layers; it does not fill the open cavity where the water will go.
This is the lowest-density version in the test and provides the baseline for comparing material use and print time.
Configure the vase in PrusaSlicer using a 0.20 mm layer height and 15% infill for the first waterproofing test.
Step 8: Increase the Infill to 50%
Change the infill density to 50%, keeping the gyroid pattern, and slice again.
The estimates increased to:
- Print time: approximately 4 hours 30 minutes.
- Filament use: almost 12 meters.
Compared with the 15% version, that is about 1 hour 45 minutes of additional printing.
The denser internal structure requires more extrusion, but whether it improves water retention is a separate question. That is what the water test will check.
Compare different infill percentages in PrusaSlicer to evaluate their impact on print time, material consumption, and waterproofing.
Step 9: Slice at 100% Infill with Rectilinear
Set the infill density to 100%.
In the workflow shown in the video, PrusaSlicer warns that gyroid is unsuitable for this full-density setting. Switch the pattern to rectilinear and slice again.
Rectilinear uses straight paths, alternating direction between layers. At 100%, the slicer fills the infill regions without the deliberate spacing used for sparse infill.
However, 100% infill is a toolpath setting, not a guarantee that a physical print contains no microscopic gaps or cannot leak.
The estimates for this version were:
- Print time: just under 4 hours.
- Filament use: approximately 14.5 meters.
It used the most filament, yet its estimated print time was lower than the 50% gyroid version.
Because the pattern changed as well as the density, this is not a comparison of density alone. It shows how the combination of infill pattern and density can affect slicing estimates.
Increasing infill to 50% raises the estimated print time and filament consumption compared to the 15% infill version.
| Infill density | Infill pattern | Estimated print time | Estimated filament use |
|---|---|---|---|
| 15% | Gyroid | About 2 h 45 min | Just under 10 m |
| 50% | Gyroid | About 4 h 30 min | Almost 12 m |
| 100% | Rectilinear | Just under 4 h | About 14.5 m |
These estimates apply to the model and print profile used here. Other profiles, printers, and geometries will produce different results.
Step 10: Export the G-code and Print All Three Versions
Export a separate G-code file for each configuration.
Use filenames that clearly identify the settings, such as:
vase-15-percent-gyroid.gcodevase-50-percent-gyroid.gcodevase-100-percent-rectilinear.gcode
Print all three on the same printer using the same material.
If you repeat the experiment, also keep perimeter count, solid-layer settings, temperatures, and other print settings consistent. Record those settings so you can distinguish the effect of infill from other changes.
Three identical vase designs with different infill densities—15%, 50%, and 100%—to test how infill affects water resistance in 3D prints.
Step 11: Fill the Vases and Check for Leaks
After printing, fill each vase with water and check for leakage.
None of the three vases showed water leakage after five days.
| Infill density | Five-day water test |
|---|---|
| 15% | No leakage observed |
| 50% | No leakage observed |
| 100% | No leakage observed |
For this particular model and printing setup, increasing infill above 15% provided no observed improvement in water retention.
The lowest-infill version already passed the test while using the least filament and having the shortest estimated print time.
Comparison of estimated print time and filament consumption at 15%, 50%, and 100% infill. Higher infill uses more filament but does not always increase print time.
Step 12: Understand Why Lower Infill Worked
A printed container holds water when its walls and bottom form a continuous barrier. Increasing the amount of material behind that barrier does not necessarily fix a gap in the barrier itself.
In this experiment, the 15% version already had a sufficiently sealed wall and base to hold water for the five-day test.
That supports a practical conclusion:
This vase did not need high infill to hold water under the conditions tested.
It does not establish that infill never matters. Infill can support solid layers above it, and different geometry or slicing settings may change the outcome.
It is also useful to distinguish the modeled 3 mm shell thickness from the slicer’s perimeter count. Both influence the printed structure, but they are different settings.
Testing three 3D-printed vases with different infill percentages to see whether they can hold water without leaking.
Step 13: Apply the Results to Your Own Prints
Start with a modest infill setting and inspect the sliced walls and base before committing to a long print.
If a container leaks, investigate the perimeter paths, seams, bottom layers, and extrusion quality. Increasing infill alone may leave the actual leak path unchanged.
For a repeatable home test:
- Fill each container to the same water depth.
- Place it on a dry surface that makes leaks easy to spot.
- Check the underside and walls at consistent intervals.
- Repeat promising settings with additional prints.
The results here cover one print at each infill setting, one geometry, and a five-day observation period. The source workflow does not specify the filament type, perimeter count, or number of solid bottom layers, so it is not a complete recipe for reproducing the result.
Taller containers filled to a greater depth place more water pressure on their lower walls and base. They need their own testing, even if a smaller vase holds water successfully.
Watch the Full Video
Watch the complete workflow below to see the Fusion modeling steps, PrusaSlicer comparisons, and printed test pieces.
If you enjoy practical 3D printing experiments and Fusion projects, subscribe to The Maker Letters.
For another modeling project, watch “This Simple Trick Builds a Perfect Honeycomb Pattern.”
Key Takeaways
- The vase starts with a 50 mm diameter circle, a 50 mm extrusion, and a 15° outward taper.
- Removing the top face with Shell at 3 mm inside thickness creates the open container.
- All three versions used a 0.2 mm layer height and were printed on a Prusa i3 MK3S+.
- 15%, 50%, and 100% infill all held water with no leakage observed after five days.
- The 15% gyroid version used the least filament and had the shortest estimated print time.
- The 100% rectilinear version sliced faster than 50% gyroid, illustrating the influence of infill pattern.
- Watertightness depends on the printed walls and bottom forming a continuous barrier; high infill alone does not guarantee it.
- Treat these findings as a result for this specific setup, and test your own containers before relying on them.
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