I print over 10 pounds of material each week using 3D printing – these are the filaments I recommend

The test focuses on a few details: dimensional accuracy, roll accuracy, and print quality. Winding accuracy is a visual test where I check to make sure the filament is running well on the spool, without any crossovers that can cause snags during printing.

Print quality is done using the CNET calibration test that I use to test all of the 3D printers I review. When checking thread quality, I look for noticeable roughness and missing threads where moisture or other contaminants have interrupted the melting and cooling process.

Dimensional accuracy is perhaps the most important test because it measures the consistency of the threads. As you move, the filament diameter changes and will cause the filament to be extruded into the 3D printer to increase or decrease. This creates noticeable scarring in your form, or worse, complete failure. You want the material to have the same diameter all the way through.

To measure accuracy, I took a 5-meter (16.4-foot) piece of string from the beginning, middle, and end of the coil, and measured the diameter at four equally spaced points. I then add up all those measurements and divide the sum by 12 — the total number of measurements taken — to give me an average across the roll. Most modern printers use a 1.75mm filament, so you want your filament to be as close to that as possible.

Fine threads have a contrast of plus or minus 0.02mm, fine threads are plus or minus 0.03mm and rough threads are anything plus or minus 0.05mm. All of the threads we’ve recommended here average at least 0.03mm.