I Tested 5 PLA brands (6 spools) across 5 break tests - the price didn't convert into strength. Here's the data.
I ran a break test on six PLA filaments priced between $13 and $60 CAD/kg.
Five tests: tensile (dogbone along the print), layer adhesion (dogbone rotated 90°), M3 screw pull-out, dimensional accuracy, and warping. Three samples per mechanical test. Same printer, same settings, same Prusa MK4 profile throughout.
The tensile result was what you'd expect — Prusament won at 62.2 kg average, budget PLA came in at 54.8 kg. Twelve kilograms spread across the full range.
Layer adhesion is where it fell apart. Polymaker ($25) topped out at 12.8 kg. The $13 budget spool hit 9.9 kg. Prusament at $60: 7.2 kg. The most expensive filament had the fourth-worst layer adhesion in the test. I ran those numbers three times.
Screw pull-out flipped the leaderboard again — Prusament recovered to 87.9 kg, budget PLA at 85.5 kg, two and a half kilos separating them. Bambu Tough+ ($31) came in dead last at 67.1 kg — which makes sense once you understand why it was the only filament that didn't shatter in the layer adhesion test.
Warping: all six zero corner lift, smooth PEI, 60°C bed, no brim. Nothing to report there.
Full test breakdown, raw data, and the filament rankings with and without price weighting: https://www.youtube.com/watch?v=LXaA9NUTj0M
Curious if anyone has seen different layer adhesion results with Prusament - my samples came straight from sealed packaging, no drying.