{
  "opening": "PolyLite PETG's sheet lists drying at 65 °C (149 °F) for 6 h, a nozzle of 220–250 °C (428–482 °F), and a bed of 70–90 °C (158–194 °F). The supplied comments talk about fan speed and retraction, not about a measured moisture percentage. A weak part in those comments is a cooling comment. It is not a datasheet failure load.",
  "question": "Why is my PETG brittle or weak?",
  "slug": "petg_brittle",
  "useCase": "petg",
  "useCaseLabel": "PETG",
  "updated": "2026-10-26",
  "shortAnswer": "PolyLite PETG's sheet lists drying at 65 °C (149 °F) for 6 h, a nozzle of 220–250 °C (428–482 °F), and a bed of 70–90 °C (158–194 °F). The supplied comments talk about fan speed and retraction, not about a measured moisture percentage. A weak part in those comments is a cooling comment. It is not a datasheet failure load.",
  "recommendedMaterials": [
    "petg"
  ],
  "printerConsiderations": [
    "A comment says any fan from 0% to 100% can be right, and that a lower fan strengthens layer adhesion. prints at about 25–30% fan and says that is already pushing it. Those are comments. None of the three sheets above lists a fan percent.",
    "A comment uses retraction of 30–40 mm/s and 1.8 mm on a direct drive, against a tower that suggested 1.2 mm. That is the comment's result. It is not a PolyLite retraction cell.",
    "Drying is 65 °C (149 °F) for 6 h, 65 °C (149 °F) for 8 h, or 60 °C (140 °F) for 8 h on these three rows. One shared dry cycle would mis-state at least one of them."
  ],
  "pros": [
    "The dry cycles are the sheets. The fan and retraction numbers stay on the comments.",
    "Three PETG rows show that brittle is not diagnosed by copying a single nozzle."
  ],
  "cons": [
    "No comments states a moisture percentage or a nozzle that was too low."
  ],
  "community": "The editorial summary says brittle PETG usually means wet filament or too low a temperature. The excerpts are about cooling and retraction. r/FixMyPrint 14si4e1, score 3, says fan from 0% to 100% depends on the use, and that a lower fan strengthens layer adhesion. Score 2 prints at about 25–30% fan and says the plastic is cured 5 mm out of the nozzle, so too much cooling sticks a new line to a cold layer. r/FixMyPrint 15spxqy, score 5, uses slower retraction at 30–40 mm/s and 1.8 mm on direct drive instead of 1.2 mm from a tower. Score 1 blames a Bowden tube for ooze. No excerpt was supplied for r/BambuLab 1mayxjb, r/3Dprinting zfo9rp, or r/BambuLab 1dqnmr9.",
  "related": [
    "petg_print",
    "brittle",
    "dry_petg",
    "layer_adh"
  ],
  "faq": [
    {
      "q": "Why is my PETG brittle or weak?",
      "a": "PolyLite PETG's sheet lists drying at 65 °C (149 °F) for 6 h, a nozzle of 220–250 °C (428–482 °F), and a bed of 70–90 °C (158–194 °F). The supplied comments talk about fan speed and retraction, not about a measured moisture percentage. A weak part in those comments is a cooling comment. It is not a datasheet failure load."
    },
    {
      "q": "Should I dry it, or turn the fan down?",
      "a": "The sheets publish a dry cycle: 65 °C (149 °F) for 6 h on PolyLite PETG, 65 °C (149 °F) for 8 h on Bambu PETG HF, and 60 °C (140 °F) for 8 h on ELEGOO Rapid PETG. The comments publish fan and retraction. [Dry PETG](/answers/dry_petg) is the hour table. [Layer adhesion](/answers/layer_adh) is the bond page. [PETG printing](/answers/petg_print) is the setup page. [Brittle filament](/answers/brittle) is mostly about PLA spools that snap. Do not collapse those into one knob."
    },
    {
      "q": "Is 25–30% fan the PETG rule?",
      "a": "It is on r/FixMyPrint. on the same thread says the useful fan can be anywhere from 0% to 100%. The PolyLite, Bambu, and ELEGOO rows cited here do not list a fan percent."
    }
  ],
  "sources": [
    {
      "title": "Polymaker PolyLite PETG technical data sheet",
      "url": "https://cdn.shopify.com/s/files/1/0548/7299/7945/files/PolyLite_PETG_TDS_EN_V5.4.pdf",
      "kind": "datasheet"
    },
    {
      "title": "Bambu Lab PETG HF technical data sheet",
      "url": "https://store.bblcdn.com/ce12d65176a94f1086e6aefa238e62e2.pdf",
      "kind": "datasheet"
    },
    {
      "title": "ELEGOO Rapid PETG product page",
      "url": "https://us.elegoo.com/products/rapid-petg-filament-1-75mm-colored-1kg",
      "kind": "manufacturer"
    },
    {
      "title": "Community source, r/FixMyPrint 14si4e1",
      "url": "https://www.reddit.com/r/FixMyPrint/comments/14si4e1/",
      "kind": "reddit"
    },
    {
      "title": "Community source, r/FixMyPrint 15spxqy",
      "url": "https://www.reddit.com/r/FixMyPrint/comments/15spxqy/",
      "kind": "reddit"
    },
    {
      "title": "Community source, r/BambuLab 1mayxjb",
      "url": "https://www.reddit.com/r/BambuLab/comments/1mayxjb/",
      "kind": "reddit"
    },
    {
      "title": "Community source, r/3Dprinting zfo9rp",
      "url": "https://www.reddit.com/r/3Dprinting/comments/zfo9rp/",
      "kind": "reddit"
    },
    {
      "title": "Community source, r/BambuLab 1dqnmr9",
      "url": "https://www.reddit.com/r/BambuLab/comments/1dqnmr9/",
      "kind": "reddit"
    }
  ],
  "recommendations": [
    {
      "rank": 1,
      "note": "Technical data sheet, drying checked 18 October 2026, lists a nozzle of 220–250 °C (428–482 °F), a bed of 70–90 °C (158–194 °F), and drying at 65 °C (149 °F) for 6 h. Heat dataset, checked 21 October 2026, lists HDT 78 °C (172 °F) at 0.45 MPa and 75 °C (167 °F) at 1.8 MPa, ISO 75. No brittleness test is stored.",
      "brand": "Polymaker",
      "product": "Polylite PETG",
      "material": "PETG",
      "url": "/brand/polymaker/polylite-petg",
      "nozzle": "220–250 °C (428–482 °F)",
      "bed": "70–90 °C (158–194 °F)",
      "pricePerKg": null,
      "datasheetUrl": "https://cdn.shopify.com/s/files/1/0548/7299/7945/files/PolyLite_PETG_TDS_EN_V5.4.pdf",
      "affiliateUrl": null
    },
    {
      "rank": 2,
      "note": "Technical data sheet, drying checked 18 October 2026, lists a nozzle of 230–260 °C (446–500 °F), a bed of 65–75 °C (149–167 °F), and drying at 65 °C (149 °F) for 8 h. The hour count is this spool. It is not PolyLite's 6 h.",
      "brand": "Bambu Lab",
      "product": "PETG HF",
      "material": "PETG",
      "url": "/brand/bambu-lab/petg-hf",
      "nozzle": "230–260 °C (446–500 °F)",
      "bed": "65–75 °C (149–167 °F)",
      "pricePerKg": null,
      "datasheetUrl": "https://store.bblcdn.com/ce12d65176a94f1086e6aefa238e62e2.pdf",
      "affiliateUrl": null
    },
    {
      "rank": 3,
      "note": "ELEGOO Rapid PETG lists drying at 60 °C (140 °F) for 8 h on the 1 kg page checked 17 October 2026, with a nozzle of 240–270 °C (464–518 °F) and a bed of 65–75 °C (149–167 °F). A third spool, a third dry cycle.",
      "brand": "ELEGOO",
      "product": "RAPID PETG",
      "material": "PETG",
      "url": "/brand/elegoo/rapid-petg",
      "nozzle": "240–270 °C (464–518 °F)",
      "bed": "65–75 °C (149–167 °F)",
      "pricePerKg": null,
      "datasheetUrl": null,
      "affiliateUrl": null
    }
  ]
}