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Most filament buying decisions are based on brand reputation and price. I wanted actual break data — so I ran a blind mechanical test on six PLA spools from five brands, ranging from $13 to $60 CAD/kg, using the same printer, the same settings, and the same geometry for every spool. The results don't match the price tags.
This article covers all five tests with full data tables and ranked results. If you're choosing filament for functional 3D printed parts or 3D printed RC cars, the layer adhesion result is the one you need to see first.
Test Setup and Methodology
Six spools from five brands were printed blind — numbered before printing, labels hidden until all results were recorded. All spools came from factory-sealed packaging with no prior drying. This tests real-world out-of-box performance, not optimised conditions. All prices are actual buying prices in Canadian dollars (CAD).
Filaments Tested
| # | Brand | Type | Price (CAD/kg) | Source |
|---|---|---|---|---|
| 1 | 3D Printing Canada Budget PLA | PLA | ~$13 | 3D Printing Canada |
| 2 | eSUN | PLA | ~$19 | Amazon CA |
| 3 | Polymaker | PLA | ~$25 | Amazon CA |
| 4 | Bambu Lab Basic | PLA Basic | ~$30 | Bambu direct |
| 4+ | Bambu Lab Tough+ | PLA Tough+ | ~$31 | Bambu direct |
| 5 | Prusament | PLA | ~$60 | 3D Printing Canada |
Print Settings (identical for all filaments)
- Printer: Prusa MK4, 0.4mm nozzle
- Nozzle: 220°C / Bed: 60°C
- Layer height: 0.15mm
- Walls: 5 (= 2.0mm per side — 4mm waist is 100% perimeter, no infill in gauge zone)
- Infill: 50% Gyroid
- Cooling: 100% after layer 1
Three samples per filament for mechanical tests. One sample per filament for dimensional accuracy and warping.
Test 1: Tensile Strength Along the Print Direction
Prusament won at 62.2 kg average. The $13 budget PLA came in third at 54.8 kg — 13% weaker for one-fifth the price.
| Filament | Run 1 (kg) | Run 2 (kg) | Run 3 (kg) | Average (kg) |
|---|---|---|---|---|
| Prusament ($60) | 64.55 | 60.95 | 61.05 | 62.18 |
| Bambu Tough+ ($31) | 56.80 | 56.85 | 56.45 | 56.70 |
| Budget PLA ($13) | 56.85 | 54.10 | 53.55 | 54.83 |
| eSUN ($19) | 54.35 | 51.60 | 52.80 | 52.92 |
| Polymaker ($25) | 57.25 | 46.50 | 54.25 | 52.67 |
| Bambu Basic ($30) | 49.30 | 52.15 | 48.15 | 49.87 |
Transparency note on Polymaker: Run 2 came in at 46.5 kg against 57.25 and 54.25 for the other two samples. Kept in the average — either a micro-defect in that specimen or a real inconsistency in the material. The outlier is why Polymaker's tensile average looks lower than its layer adhesion result would suggest.
Test 2: Layer Adhesion Across Layer Interfaces
Layer adhesion is the failure mode that matters most for functional FDM parts — most real-world breaks happen across layer lines, not along them. This is where price completely stopped predicting performance.
| Filament | Run 1 (kg) | Run 2 (kg) | Run 3 (kg) | Average (kg) |
|---|---|---|---|---|
| Polymaker ($25) | 11.55 | 14.00 | 12.85 | 12.80 |
| Bambu Tough+ ($31) | 10.70 | 12.90 | 11.30 | 11.63 |
| Budget PLA ($13) | 10.05 | 11.30 | 8.30 | 9.88 |
| Bambu Basic ($30) | 7.45 | 8.70 | 7.50 | 7.88 |
| Prusament ($60) | 6.95 | 7.05 | 7.45 | 7.15 |
| eSUN ($19) | 4.95 | 5.00 | 4.65 | 4.87 |
Every filament fractured explosively — except Bambu Tough+. Tough+ cracked but stayed in one piece across all three runs. That ductile failure mode is directly relevant for suspension and impact parts that cannot throw fragments on failure.
Test 3: M3 Screw Pull-Out Resistance
Prusament recovered here — 87.9 kg, top of the group. Budget PLA followed at 85.5 kg, just 2.4 kg behind. Bambu Tough+ came in last at 67.1 kg — the same ductile behavior that kept it intact in layer adhesion made it weaker under concentrated axial load.
| Filament | Run 1 (kg) | Run 2 (kg) | Run 3 (kg) | Average (kg) |
|---|---|---|---|---|
| Prusament ($60) | 91.65 | 97.65 | 74.35 | 87.88 |
| Budget PLA ($13) | 79.70 | 87.55 | 89.20 | 85.48 |
| eSUN ($19) | 80.90 | 83.30 | 82.70 | 82.30 |
| Polymaker ($25) | 82.45 | 90.50 | 66.15 | 79.70 |
| Bambu Basic ($30) | 74.95 | 79.60 | 82.30 | 78.95 |
| Bambu Tough+ ($31) | 67.40 | 66.85 | 67.15 | 67.13 |
Test 4: Dimensional Accuracy
Bambu Basic was the most accurate filament — just 0.02mm undersized on width, exact on height. Prusament came in at 0.11mm undersized. Bambu Tough+ was the worst at 0.145mm — despite coming from the same manufacturer as Basic, for $1 more.
| Filament | Width Deviation (mm) | Height Deviation (mm) | 6.33mm Bit Fit |
|---|---|---|---|
| Bambu Basic ($30) | −0.020 | 0.000 | Yes |
| Budget PLA ($13) | −0.050 | 0.000 | Yes |
| Polymaker ($25) | −0.035 | −0.050 | Yes |
| eSUN ($19) | −0.085 | −0.040 | Yes (6.6mm hole) |
| Prusament ($60) | −0.110 | −0.010 | Yes |
| Bambu Tough+ ($31) | −0.145 | −0.010 | Yes |
The $13 budget spool printed more dimensionally accurate parts than the $60 Prusament. All six filaments fit the 6.33mm screwdriver bit. eSUN required a 6.6mm designed hole versus 6.55mm for the other five — slightly more shrinkage on circular features. For tight-tolerance fits in functional printed parts, always calibrate shrinkage per filament — don't assume nominal dimensions transfer.
Test 5: Warping
All six filaments printed with zero corner lift — smooth PEI bed, 60°C, no brim. No meaningful differences between brands at standard settings. Warping is a non-issue for PLA across this price range when bed adhesion is properly set up.
Overall Rankings: Performance vs Value
Physical Performance Only (Price Excluded)
Each test scored 0–10 relative to the best and worst result in that test. Higher is better. All five categories weighted equally.
| Filament | Tensile | Layer Adhesion | Screw Pull-Out | Dimensional | Warping | Total /50 |
|---|---|---|---|---|---|---|
| Polymaker ($25) | 8.5 | 10.0 | 9.1 | 9.9 | 10.0 | 47.5 |
| Budget PLA ($13) | 8.8 | 7.7 | 9.7 | 9.8 | 10.0 | 46.0 |
| Prusament ($60) | 10.0 | 5.6 | 10.0 | 9.3 | 10.0 | 44.9 |
| Bambu Tough+ ($31) | 9.1 | 9.1 | 7.6 | 9.0 | 10.0 | 44.8 |
| Bambu Basic ($30) | 8.0 | 6.2 | 9.0 | 10.0 | 10.0 | 43.2 |
| eSUN ($19) | 8.5 | 3.8 | 9.4 | 9.5 | 10.0 | 41.2 |
Value-Weighted Ranking (Price Included)
Price scored 0–10 inverted: cheapest = 10, most expensive = 0.
| Filament | Price (CAD/kg) | Price Score | Physical /50 | Total /60 |
|---|---|---|---|---|
| Budget PLA | $13 | 10.0 | 46.0 | 56.0 |
| Polymaker | $25 | 5.2 | 47.5 | 52.7 |
| Bambu Tough+ | $31 | 4.2 | 44.8 | 49.0 |
| eSUN | $19 | 6.8 | 41.2 | 48.0 |
| Bambu Basic | $30 | 4.3 | 43.2 | 47.5 |
| Prusament | $60 | 2.2 | 44.9 | 47.1 |
Which PLA Should You Buy?
The right answer depends on what your part needs to survive.
- Most hobby RC and maker parts: Budget PLA at $13 CAD/kg. Competitive on tensile and screw pull-out, outperforms Prusament on layer adhesion, best value overall. For structural RC car parts like suspension arms and motor mounts, this is the default recommendation.
- Layer adhesion priority: Polymaker PLA at $25 CAD/kg. Dominated this test at 12.8 kg and won overall physical performance. The right choice for parts that bend or flex across the layer direction.
- Impact parts that cannot fragment: Bambu Tough+. The only filament that deformed rather than shattered. If failure mode matters as much as failure load, Tough+ is the only option that passed that test.
- Tensile and screw retention, cost no object: Prusament. It won both those tests. You're paying for consistency — not for across-the-board superiority.
Frequently Asked Questions
Is expensive PLA filament actually stronger?
For tensile strength along the print axis, yes — but the margin is 13% for 5× the price. For layer adhesion, the $60 Prusament placed 4th of 6, below the $13 budget spool. Strength depends on which test you run.
Which PLA has the best layer adhesion?
Polymaker PLA at ~$25 CAD/kg — 12.8 kg average on the 90° dogbone pull. Budget PLA placed third at 9.9 kg. Prusament placed fourth at 7.2 kg. eSUN was weakest at 4.87 kg.
What is the difference between Bambu PLA Basic and Tough+?
Tough+ outperforms Basic in tensile and layer adhesion but loses in screw pull-out (by 12 kg) and dimensional accuracy (7× worse). Tough+ deforms rather than shatters. Use Tough+ for layer-line tension and impact; Basic for threaded hardware and tight-tolerance fits.
Is Prusament worth the price?
For tensile and screw retention — yes. For overall value — no. When price is factored into a 6-category score, Prusament finishes last. It's paying for specific test wins and consistency, not across-the-board superiority.
Does filament brand affect dimensional accuracy?
Yes. The range in this test was 0.02mm (Bambu Basic) to 0.145mm (Bambu Tough+) undersize on a 20mm nominal width. Prusament printed 0.11mm undersize — more than the $13 budget spool at 0.05mm. Calibrate per filament for tight fits.
Does PLA brand affect warping?
Not at standard settings. All six filaments printed with zero corner lift on smooth PEI at 60°C bed with no brim. Warping is more a function of bed preparation than filament brand for standard PLA.