3D Printing InfoFilament comparison
Magnetic vs PCTG
Compare printing settings, strength, heat resistance, dated prices and sources.
2 selected · all documented properties
| Property | Magnetic filamentSPECIALTY | PCTGPETG |
|---|---|---|
| Market snapshot | ||
| Listing priceUSD/kg; dated snapshots | $64.99/kg median; $64.99–$64.99/kg across 1 dated product listings | $34.99/kg median; $14.00–$50.67/kg across 5 dated product listings |
| Identity & Market | ||
| Base polymer / chemistry | PLA loaded with ferromagnetic iron powder, so printed parts respond to magnets[1] | Poly(cyclohexylenedimethylene terephthalate) glycol — a copolyester with a higher cyclohexanedimethanol content than PETG[2][3] |
| Densityg/cm³ | About 1.85 (Proto-pasta manufacturer figure) — 1.5× standard PLA[1] | 1.23 (Extrudr, ASTM D792; 3DXTech, ISO 1183)[3][4] |
| Typical priceUSD/kg | 1 kg spools cluster near 65[5] | 1 kg spools cluster near 34[6][4][5] |
| Price range across brandsUSD/kg | 64–70 across formats; 1 kg spool 65, 500 g 70, 2 kg 70[5] | 14–51 across brands; CHCKX 14 in a 10-roll bundle, Push Plastic 30, Proto-pasta 35 at 1 kg, 3DXTech 51[6][4][7] |
| Market availability1–5 | Niche, a handful of specialist brands[5] | Available from several mainstream brands[6][4][5][8] |
| Spool sizes & diameters | 1.75 and 2.85 mm; 0.1, 0.5, 1 and 2 kg spools[5] | 1.75 and 2.85 mm; 0.5, 0.75, 1, 3 and 5 kg spools[6][5][4] |
| Typical applications | Sensor targets, magnetic fixtures, and props that need to stick to a magnet or rust deliberately[1] | Transparent covers, guards and impact-loaded parts where PETG cracks[2][3] |
| Printing Parameters | ||
| Nozzle temperature°C | 192 (Proto-pasta)[1] | 250–270 (Spectrum, Extrudr)[2][3] |
| Bed temperature°C | 60 (Proto-pasta)[1] | 60–100 (Spectrum)[2] |
| Enclosure / chamber requirement1–5 | Open frame is fine[1] | Open frame is fine — Spectrum and Extrudr both say a closed chamber is not necessary, Extrudr adds it helps on larger parts[2][3] |
| Part cooling fan | Not documented | Up to 100 % (Spectrum); 20–50 % (Extrudr)[2][3] |
| Bed surface & adhesion aid | Not documented | Textured PEI, satin or powder-coated sheets; on smooth PEI a glue stick acts as a release agent[9][10] |
| Maximum volumetric flow (mm³/s; see test conditions)mm³/s | 1.6–2.4 at Proto-pasta's 20–30 mm/s on a 0.4 mm nozzle at 0.2 mm layer[1] | 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[3][11] |
| Bed-adhesion difficulty1–5 | Not documented | Needs the right surface or a thin adhesive — the problem is releasing the part, not sticking it[9][10] |
| Stringing / oozing tendency1–5 | Not documented | Moderate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[10] |
| Shrinkage% | Not documented | 0.2–0.5 (Extrudr, ASTM D955)[3] |
| Overall printing difficulty1–5 | Intermediate — dry filament and a tuned profile; slow, and brittle in filament form[1] | Easy — minor profile tuning[2][3] |
| Extruder requirement | Proto-pasta advises an extrusion width 0.05 mm larger than the nozzle and warns feeding is inconsistent below 0.4 mm and on Bowden machines[1] | Not documented |
| Hardware Wear & Reliability | ||
| Nozzle hardness required1–4 | Brass acceptable; hardened steel for volume work[1] | Brass fine indefinitely — Extrudr explicitly states no hardened nozzle is needed[3] |
| Abrasiveness1–5 | Moderately abrasive — metal fill[1] | Non-abrasive[3] |
| Nozzle clog risk1–5 | Moderate — needs dry filament and a clean nozzle; Prusa lists metal-filled composites as a higher clogging risk and recommends a 0.6 mm nozzle minimum[12] | Low — 3DXTech lists no special nozzle concerns and no minimum layer height for PCTG, only a 65 °C pre-dry[13] |
| Heat-creep / jam sensitivity1–5 | Not documented | Slightly sensitive[14] |
| Hotend requirement | Proto-pasta recommends a wear-resistant or larger nozzle for longer service intervals[1] | No special hot-end required[14] |
| Moisture Behaviour | ||
| Moisture absorption (hygroscopicity)1–5 | Not documented | 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[9][13] |
| Symptoms when wet | Not documented | Bubbling and popping at the nozzle, stringing and a rough surface[15] |
| Effect of moisture on strength | Polymaker rates PLA low-sensitivity and publishes no dry-versus-conditioned figures; absorbed water flashes to steam and shows as bubbling and poor layer adhesion[15] | 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[15] |
| Storage requirement | Not documented | Sealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[15][10] |
| Mechanical Properties | ||
| Tensile strength (XY)MPa | Not documented | 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[2][3][16] |
| Elongation at break% | Not documented | 215–220 at break on moulded specimens (ISO 527); 4.3–4.4 at yield[2][3] |
| Charpy impact, notchedkJ/m² | Not documented | 93–94 notched Izod at 23 °C on moulded specimens (ISO 180); 3DXTech quotes 8 by ISO 180/A[2][3][4] |
| Other impact data | Not documented | Izod 4.14 kJ/m² on My Tech Fun printed bars, against 3.37 for PETG on the same rig[16] |
| Layer adhesion / Z tensileMPa | Not documented | 21.6 on My Tech Fun 4×4 mm printed bars, against 32.9 for PETG[16] |
| Brittleness1–5 | Brittle — Proto-pasta describes the filament as more brittle than standard PLA and needing extra care in handling[1] | Tough — absorbs impact, yields before breaking[2][3] |
| Hardness (scale-specific)Shore A / Shore D / Rockwell | Not documented | 69 Shore D measured by My Tech Fun, against 72 for PETG[16] |
| Creep resistance / sustained load1–5 | Not documented | Below average — a 12 mm bar sagged to 19.4 mm over 5 days at 1.25 kg, slightly worse than PETG's 18.2[16] |
| Fatigue / repeated-flex resistance1–5 | Not documented | Good — 215 % elongation at break and 94 kJ/m² notched Izod on moulded specimens (Extrudr, Spectrum)[2][3] |
| Elasticity / flexibility1–5 | Rigid[1] | Slightly flexible in thin sections[16] |
| Thermal Properties | ||
| Glass transition (Tg)°C | Not documented | 78 (3DXTech, DSC)[4] |
| Melting point / Vicat°C | Not documented | Amorphous — no melting point; Vicat 88 (Spectrum, Extrudr)[2][3] |
| Continuous service temperature°C | Not documented | 68 — loaded bars begin to move at this temperature, against 65 for PETG[16] |
| Flammability / UL 94 | Not documented | Flammable; no UL 94 rating published for standard grades[17] |
| Environment & Chemical | ||
| Outdoor durability | Deliberately rustable — Proto-pasta markets the iron content as oxidising when exposed to moisture[1] | Not documented |
| Chemical resistance | Not documented | Withstands acids, alkalis, oils and UV exposure[10] |
| Water / humidity resistance in service1–5 | Not documented | Good — minor absorption; Spectrum describes the polymer as hydrophobic[2] |
| Food contact | Not documented | Not certified for food contact as filament[10] |
| Biodegradability / compostability | Not documented | Not biodegradable[10] |
| Recyclability | Not documented | Not accepted in household plastic collection[10] |
| Electrical & ESD properties | Ferromagnetic: Proto-pasta states it responds to magnets and behaves similarly to pure iron[1] | Surface resistance above 10¹³ ohm/sq — insulating (3DXTech, ASTM D257)[4] |
| Health & Safety | ||
| Fume toxicity1–5 | Low hazard — minimal VOC and particle emission; none of these materials was in the chamber study[18] | Moderate — measurable VOCs and UFPs, ventilation advised[18] |
| Ventilation / filtration requirement1–5 | Open a window / occasional ventilation[18] | Open a window / occasional ventilation[18] |
| Post-Processing | ||
| Sanding & machining | Polishing and deliberate rusting are the intended finishes[1] | Sands poorly — the material is tough and gums rather than powders[14] |
| Gluing & solvent welding | Not documented | Cyanoacrylate; no common solvent welds PETG cleanly[14] |
| Vapour / chemical smoothing | Not documented | No practical vapour smoothing[14] |
| Support material pairing | Not documented | Prints its own supports; Polymaker rates PolyDissolve S1 for PETG[14] |
| Dimensional accuracy & detail | Not documented | Optical clarity is the selling point; Extrudr recommends a layer height at most 50 % of nozzle diameter[3] |
| Solvents & Solubility | ||
| Soluble in | Chloroform dissolves the PLA matrix and leaves the iron powder behind; laboratory reagent, not workshop stock.[19][1] | No common workshop solvent; Eastman's CHDM copolyester data shows 1,2-dichloroethane destroying it within a week.[20] |
| Softened or crazed by | Acetone and ethyl acetate plasticise the matrix rather than dissolving it; water attacks the exposed iron.[19][1] | Acetone, ethyl acetate, toluene and DMF swell and soften the copolyester; methanol crazes it (Eastman, 1 y at 23 °C).[20] |
| Solvent welding & smoothing agent | None — PLA has no workshop-safe solvent, and the iron loading blocks the surface flow smoothing needs.[19] | Dichloromethane brushed on is the only agent that smooths PETG — a controlled carcinogen, not workshop stock.[21] |
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
- Magnetic Iron PLA — product page and technical data Proto-pasta · 2026-08 · tds
- Spectrum Premium PCTG Technical Data Sheet Spectrum Filaments · 2026-08 · tds
- Extrudr PCTG technical data Extrudr · 2026-08 · tds
- MAX-G PCTG Technical Data Sheet 3DXTech · 2026-08 · tds
- Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
- Push Plastic product catalogue Push Plastic · 2026-08 · vendor
- CHCKX 10KG Multicolor PCTG Filament bundle CHCKX (Amazon US) · 2026-08 · vendor
- Atomic Filament product catalogue Atomic Filament · 2026-08 · vendor
- Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
- PETG — material basics Polymaker Wiki · 2026-08 · doc
- Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
- Composite materials with metal or wood particles Prusa Knowledge Base · 2026-08 · doc
- MAX-G PCTG — product page (print recommendations) 3DXTech · 2026-08 · doc
- PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
- Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
- PCTG vs PETG comparison — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
- Prusament PETG V0 Technical Datasheet Prusa Polymers · 2026-08 · tds
- 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
- Solubility Study of Ingeo Biopolymer Grades in Common Organic Solvents (NWPD003) NatureWorks · 2019-10 · tds
- Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
- Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc