Before choosing a filament, start with the job the printed part needs to do. Is it a mold, vessel-placement jig, external anatomy shell, probe holder, flexible clip, or a temporary form?
Here is a quick guide to common FDM materials:
| Material | Good for | Watch-outs |
|---|---|---|
| PLA | Fast prototypes, molds, anatomy shells, alignment jigs | Can become brittle; lower heat resistance |
| PETG | Reusable molds, wet-facing fixtures, clips, durable workshop parts | Can string; fine details may need cleanup |
| TPU | Flexible frames, gaskets, compressible supports | Slow printing; less crisp geometry |
| ABS / ASA | Heat-tolerant and durable structural parts | Requires ventilation and usually an enclosure |
| Nylon | Tough, repeatedly stressed parts | Moisture-sensitive and less beginner-friendly |
| PP | Flexible, chemical-resistant parts | Can warp and be difficult to bond |
| PVA / BVOH | Dissolvable support and temporary internal channels | Moisture-sensitive and comparatively costly |
For most low-cost ultrasound-training builds, PLA and PETG are a good place to start.
PLA: fast, affordable, and excellent for learning
PLA is widely available, inexpensive, and generally easy to print successfully. It is a practical material for:
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One-off molds and casting forms
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Alignment jigs
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External anatomy shells
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Classroom prototypes
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Geometry tests before committing to a more durable build
Its main limitation is durability under heat and repeated rough handling. A part may be perfectly useful for a room-temperature prototype, but less dependable if it will sit near a warm process, be left in a hot car, or flex repeatedly during workshops.
PETG: the reusable workhorse
PETG is generally tougher than PLA and better suited to repeated handling, moisture, and modest heat exposure. We (SonoFoundry team) have poured hot ballistic gel straight into PETG moulds. However, do not stick them in the oven they will deform.
Consider PETG for:
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Reusable molds and casting fixtures
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Probe holders and transport brackets
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Clips, frames, and connectors
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Parts that will be cleaned or exposed to water
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Workshop components likely to be bumped, dropped, or packed away repeatedly
PETG can produce more stringing than PLA, so detailed prints may need a little cleanup. We have had to do a moderate amount of wet sanding to clean up PETG prints.