3D Printing Info

Filament comparison

PA blend vs PCTG

Compare printing settings, strength, heat resistance, dated prices and sources.

PA6/66 copolymer blends guidePCTG guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PA blend comparisonsMore PCTG comparisons
PA blend vs PCTG — documented properties and sources
PropertyPA6/66 copolymer blendsPAPCTGPETG
Market snapshot
Listing priceUSD/kg; dated snapshots$65.62/kg median; $62.00–$113.33/kg across 4 dated product listings$34.99/kg median; $14.00–$50.67/kg across 5 dated product listings
Identity & Market
Base polymer / chemistryPA6/66 copolymer — a nylon alloy that lowers the melting point and improves printability against straight PA6[1][2]Poly(cyclohexylenedimethylene terephthalate) glycol — a copolyester with a higher cyclohexanedimethanol content than PETG[3][4]
Densityg/cm³1.12 (ISO 1183, Polymaker CoPA)[1]1.23 (Extrudr, ASTM D792; 3DXTech, ISO 1183)[4][5]
Typical priceUSD/kg1 kg-equivalent spools cluster near 65[6][7][8]1 kg spools cluster near 34[9][5][10]
Price range across brandsUSD/kg62–113 across brands; add:north Adura 62, PrimaCreator NylonPower PA6/66 65 at 500 g, Polymaker CoPA 67, 3DXTech AmideX Nylon 6-66 113[6][11][7][8]14–51 across brands; CHCKX 14 in a 10-roll bundle, Push Plastic 30, Proto-pasta 35 at 1 kg, 3DXTech 51[9][5][12]
Market availability1–5Available from several mainstream brands[6][11]Available from several mainstream brands[9][5][10][13]
Spool sizes & diameters1.75 and 2.85 mm; 0.5, 0.75 and 1 kg spools[6][11][7][8]1.75 and 2.85 mm; 0.5, 0.75, 1, 3 and 5 kg spools[9][10][5]
Typical applicationsGeneral-purpose nylon parts and, unusually, CoPA can support itself if the support is removed before it absorbs moisture[1]Transparent covers, guards and impact-loaded parts where PETG cracks[3][4]
Printing Parameters
Nozzle temperature°C250–270 (Polymaker CoPA)[1]250–270 (Spectrum, Extrudr)[3][4]
Bed temperature°C25–50 (Polymaker CoPA)[1]60–100 (Spectrum)[3]
Enclosure / chamber requirement1–5Enclosure required (passive) — Polymaker specifies a chamber at ambient temperature[1]Open frame is fine — Spectrum and Extrudr both say a closed chamber is not necessary, Extrudr adds it helps on larger parts[3][4]
Part cooling fanNot documentedUp to 100 % (Spectrum); 20–50 % (Extrudr)[3][4]
Bed surface & adhesion aidNot documentedTextured PEI, satin or powder-coated sheets; on smooth PEI a glue stick acts as a release agent[14][15]
Maximum volumetric flow (mm³/s; see test conditions)mm³/s16 at Polymaker's 200 mm/s cap on a 0.4 mm nozzle at 0.2 mm layer[1][16]1.6–16 at the 20–200 mm/s Extrudr rates the material for, on a 0.4 mm nozzle at 0.2 mm layer[4][16]
Bed-adhesion difficulty1–5Not documentedNeeds the right surface or a thin adhesive — the problem is releasing the part, not sticking it[14][15]
Stringing / oozing tendency1–5Not documentedModerate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[15]
Shrinkage%Not documented0.2–0.5 (Extrudr, ASTM D955)[4]
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; must be kept below 20 % RH throughout[1][17]Easy — minor profile tuning[3][4]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely for unfilled grades[18]Brass fine indefinitely — Extrudr explicitly states no hardened nozzle is needed[4]
Abrasiveness1–5Non-abrasive when unfilled[18]Non-abrasive[4]
Nozzle clog risk1–5Very high — frequent jams without careful setup[19][17]Low — 3DXTech lists no special nozzle concerns and no minimum layer height for PCTG, only a 65 °C pre-dry[20]
Heat-creep / jam sensitivity1–5Not documentedSlightly sensitive[21]
Hotend requirementNot documentedNo special hot-end required[21]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Very high (>2 %) — Polymaker's own wet-state specimens reached 6.16 % moisture content after 48 h immersion at 60 °C[1][17]Moderate (0.3–0.8 %) — the copolyester matrix reaches 0.40 % saturated at 25 °C / 55 % RH and 3DXTech specifies a 65 °C, 4 h pre-dry[14][20]
Drying temperature & time100 °C for 8 h (Polymaker CoPA)[1]Not documented
Symptoms when wetPopping and cracking during extrusion, then hard-to-diagnose defects[19]Bubbling and popping at the nozzle, stringing and a rough surface[17]
Effect of moisture on strengthMeasured dry against wet on printed specimens at 6.16 % moisture (Polymaker CoPA): tensile 78.0 → 34.3 MPa, Young's modulus 2703 → 724 MPa, flexural strength 109.8 → 22.6 MPa, while notched Charpy rises 6.9 → 27.7 kJ/m² and elongation 12.7 → 13.2 %[1][19]Polymaker groups PETG with nylon, PVA and TPU as highly hygroscopic; no dry-versus-conditioned strength figures are published for this grade and the loss shows as bubbling and poor layer adhesion[17]
Storage requirementPolymaker states CoPA must always be stored and used below 20 % relative humidity[1]Sealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[17][15]
Hydrolysis at melt temperaturePolymaker requires a 100 °C dry for 8 h and storage below 20 % RH; no molecular-weight loss figure is published, and the published wet data is conditioning rather than melt hydrolysis[1][22]Not documented
Mechanical Properties
Tensile strength (XY)MPa78.0 ± 0.7 printed XY dry and 34.3 ± 2.5 wet, ISO 527 (Polymaker CoPA)[1]43–44 at yield and 45–46 at break (ISO 527, injection-moulded resin data from Spectrum and Extrudr); 48 on My Tech Fun printed bars[3][4][23]
Young's modulusMPa2703 ± 259 printed XY dry and 724 ± 61 wet, ISO 527 (Polymaker CoPA)[1]Not documented
Elongation at break%12.7 ± 2.1 printed XY dry and 13.2 ± 2.3 wet, ISO 527 (Polymaker CoPA)[1]215–220 at break on moulded specimens (ISO 527); 4.3–4.4 at yield[3][4]
Flexural strengthMPa109.8 ± 1.3 printed XY dry and 22.6 ± 0.5 wet, ISO 178 (Polymaker CoPA)[1]Not documented
Flexural modulusMPa2510 ± 25 printed XY dry and 636 ± 11 wet, ISO 178 (Polymaker CoPA)[1]Not documented
Charpy impact, notchedkJ/m²6.9 ± 1.4 printed XY dry and 27.7 ± 1.2 wet, ISO 179 notched (Polymaker CoPA) — impact quadruples when conditioned[1]93–94 notched Izod at 23 °C on moulded specimens (ISO 180); 3DXTech quotes 8 by ISO 180/A[3][4][5]
Other impact dataNot documentedIzod 4.14 kJ/m² on My Tech Fun printed bars, against 3.37 for PETG on the same rig[23]
Layer adhesion / Z tensileMPa45.8 ± 1.5 printed Z dry, falling to 13.7 ± 1.2 wet, ISO 527 (Polymaker CoPA)[1]21.6 on My Tech Fun 4×4 mm printed bars, against 32.9 for PETG[23]
Brittleness1–5Tough — absorbs impact, yields before breaking[1]Tough — absorbs impact, yields before breaking[3][4]
Hardness (scale-specific)Shore A / Shore D / RockwellShore D 86 and Rockwell 85 (108) — the source does not name the scales on extruded unfilled PA66 stock (ASTM D2240, D785)[24]69 Shore D measured by My Tech Fun, against 72 for PETG[23]
Creep resistance / sustained load1–5Not documentedBelow average — a 12 mm bar sagged to 19.4 mm over 5 days at 1.25 kg, slightly worse than PETG's 18.2[23]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[18]Good — 215 % elongation at break and 94 kJ/m² notched Izod on moulded specimens (Extrudr, Spectrum)[3][4]
Elasticity / flexibility1–5Semi-flexible[19]Slightly flexible in thin sections[23]
Z strength as % of XY%59 dry (45.8 Z against 78.0 XY) and 40 wet, printed[1]Not documented
Thermal Properties
HDT at 0.45 MPa°C111 (ISO 75, 0.45 MPa, Polymaker CoPA)[1]Not documented
HDT at 1.8 MPa°C70 (ISO 75, 1.8 MPa, Polymaker CoPA)[1]Not documented
Glass transition (Tg)°C66 (DSC, Polymaker CoPA)[1]78 (3DXTech, DSC)[5]
Melting point / Vicat°C189 melting (DSC); Vicat 180, crystallisation 148, decomposition 370 (Polymaker CoPA)[1]Amorphous — no melting point; Vicat 88 (Spectrum, Extrudr)[3][4]
Continuous service temperature°CNot documented68 — loaded bars begin to move at this temperature, against 65 for PETG[23]
Annealing response80 °C for 6 h (Polymaker CoPA)[1]Not documented
Thermal expansion (CTE)µm/m·K81.0 on extruded unfilled PA66 stock (ASTM D696; source states 4.5e-5 in/in/°F) — the same chemistry as a PA6/66 copolymer[24]Not documented
Flammability / UL 94Not documentedFlammable; no UL 94 rating published for standard grades[25]
Environment & Chemical
Chemical resistanceNot documentedWithstands acids, alkalis, oils and UV exposure[15]
Water / humidity resistance in service1–5Absorbs water, properties shift — 6.16 % uptake cost 56 % of tensile strength and 73 % of modulus[1]Good — minor absorption; Spectrum describes the polymer as hydrophobic[3]
Food contactNot documentedNot certified for food contact as filament[15]
Biodegradability / compostabilityNot documentedNot biodegradable[15]
RecyclabilityNot documentedNot accepted in household plastic collection[15]
Electrical & ESD propertiesNot documentedSurface resistance above 10¹³ ohm/sq — insulating (3DXTech, ASTM D257)[5]
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[26]Moderate — measurable VOCs and UFPs, ventilation advised[26]
VOC emission rateµg/minUp to 180 caprolactam, the dominant VOC from nylon; total VOC reached nearly 200 µg/min, the highest of the nine filaments tested[26]Not documented
Ultrafine-particle emission rateparticles/min≈2 × 10⁸ median — low for ultrafine particles despite the highest VOC mass of any filament tested[26]Not documented
Hazardous species emittedCaprolactam, at up to 180 µg/min from nylon filament — the largest single-VOC emission rate measured in the study[26]Not documented
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[26]Open a window / occasional ventilation[26]
Post-Processing
Sanding & machiningNot documentedSands poorly — the material is tough and gums rather than powders[21]
Gluing & solvent weldingNot documentedCyanoacrylate; no common solvent welds PETG cleanly[21]
Vapour / chemical smoothingNot documentedNo practical vapour smoothing[21]
Support material pairingCoPA can support itself, but Polymaker warns the support bonds permanently if it absorbs moisture before removal[1]Prints its own supports; Polymaker rates PolyDissolve S1 for PETG[21]
Dimensional accuracy & detailNot documentedOptical clarity is the selling point; Extrudr recommends a layer height at most 50 % of nozzle diameter[4]
Solvents & Solubility
Soluble inDissolved at 23 °C by formic acid above ~50 %, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — laboratory reagents.[27]No common workshop solvent; Eastman's CHDM copolyester data shows 1,2-dichloroethane destroying it within a week.[28]
Softened or crazed byZinc chloride solutions stress-crack it — 10 % marginal, 37 % not resistant; alcoholic calcium chloride dissolves it.[27]Acetone, ethyl acetate, toluene and DMF swell and soften the copolyester; methanol crazes it (Eastman, 1 y at 23 °C).[28]
Solvent welding & smoothing agentNone — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[27]Dichloromethane brushed on is the only agent that smooths PETG — a controlled carcinogen, not workshop stock.[29]

Material entries describe families or representative grades, not an interchangeable specification for every spool. Test methods, orientations and conditions may differ. Unknown values are marked “Not documented”. Prices and source dates remain historical snapshots; check the linked guide for product details. Differences highlight text, not a universal winner.

Sources for this comparison

  1. PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
  2. AmideX Nylon 6-66 — product page 3DXTech · 2026-08 · vendor
  3. Spectrum Premium PCTG Technical Data Sheet Spectrum Filaments · 2026-08 · tds
  4. Extrudr PCTG technical data Extrudr · 2026-08 · tds
  5. MAX-G PCTG Technical Data Sheet 3DXTech · 2026-08 · tds
  6. Polymaker product catalogue Polymaker · 2026-08 · vendor
  7. add:north Adura product page add:north · 2026-08 · vendor
  8. PrimaCreator SELECT NylonPower PA6/66 product page PrimaCreator · 2026-08 · vendor
  9. Push Plastic product catalogue Push Plastic · 2026-08 · vendor
  10. Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
  11. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  12. CHCKX 10KG Multicolor PCTG Filament bundle CHCKX (Amazon US) · 2026-08 · vendor
  13. Atomic Filament product catalogue Atomic Filament · 2026-08 · vendor
  14. Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  15. PETG — material basics Polymaker Wiki · 2026-08 · doc
  16. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  17. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  18. PA (Nylon) — material basics Polymaker Wiki · 2026-08 · doc
  19. Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
  20. MAX-G PCTG — product page (print recommendations) 3DXTech · 2026-08 · doc
  21. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  22. PolyMide CoPA — Technical Data Sheet page Polymaker Wiki · 2026-08 · tds
  23. PCTG vs PETG comparison — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  24. TECAMID 66 natural (PA66) — stock shape properties Ensinger · 2026-08 · tds
  25. Prusament PETG V0 Technical Datasheet Prusa Polymers · 2026-08 · tds
  26. Emissions of Ultrafine Particles and Volatile Organic Compounds from Commercially Available Desktop Three-Dimensional Printers with Multiple Filaments (Azimi et al.) Environmental Science & Technology 50(3) 1260-1268 · 2016-01 · paper
  27. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
  28. Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
  29. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc