I tested four shades of masterbatch colorants for PCTG granulate. All colors showed excellent quality – vibrant, even, and without defects. I followed the recommended dosing instructions, and the colorants blended smoothly with the PCTG material, with no clumps or residue in the extruder. The final filament had consistent coloring and printed perfectly. The shades remained stable during extrusion and printing, with no fading or pigment separation over time. These masterbatches proved to be thermally and chemically stable and easy to work with. I'm fully satisfied with the results and can recommend them for custom filament production.