Obsidian Black AF 1.75mm PCTG Filament Made in the USA!American Filament PCTG is very similar to PETG with several distinct advantages. You could even call it a PETG+! Our PCTG is made with a PET based copolyester specifically designed for professional grade 3D printing applications where easy processing and high toughness are critical. Our PCTG is made with a PET based copolyester specifically designed for professional grade 3D printing applications where easy processing and high toughness are critical.