3D Printing Info

Filament comparison

Magnetic vs PP-GF

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

Magnetic filament guideGlass-fibre PP (PP-GF) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore Magnetic comparisonsMore PP-GF comparisons
Magnetic vs PP-GF — documented properties and sources
PropertyMagnetic filamentSPECIALTYGlass-fibre PP (PP-GF)POLYOLEFIN
Market snapshot
Listing priceUSD/kg; dated snapshots$64.99/kg median; $64.99–$64.99/kg across 1 dated product listings$49.09/kg median; $46.27–$86.01/kg across 3 dated product listings
Identity & Market
Base polymer / chemistryPLA loaded with ferromagnetic iron powder, so printed parts respond to magnets[1]Polypropylene reinforced with chopped glass fibre[2][3]
Densityg/cm³About 1.85 (Proto-pasta manufacturer figure) — 1.5× standard PLA[1]1.12 (Prusament PP Glass Fiber, ISO 1183) — the glass lifts it above water[2]
Typical priceUSD/kg1 kg spools cluster near 65[4]1 kg-equivalent spools cluster near 49[5][6][7]
Price range across brandsUSD/kg64–70 across formats; 1 kg spool 65, 500 g 70, 2 kg 70[4]46-86 across brands; BCN3D PP GF30 46 at 700 g, BASF Ultrafuse PP GF30 49 at 2.2 kg, Prusament PP Glass Fiber 86 at 850 g[5][6][7]
Market availability1–5Niche, a handful of specialist brands[4]Available from several mainstream brands[5][6][7]
Spool sizes & diameters1.75 and 2.85 mm; 0.1, 0.5, 1 and 2 kg spools[4]1.75 and 2.85 mm; 700 g, 850 g and 2.2 kg spools[5][6][7]
Typical applicationsSensor targets, magnetic fixtures, and props that need to stick to a magnet or rust deliberately[1]Stiff, chemically resistant parts where PP-CF's cost or conductivity is unwanted[3]
Diameter tolerance± mmNot documented±0.04 (Prusament)[2]
Printing Parameters
Nozzle temperature°C192 (Proto-pasta)[1]245 ± 10 (Prusament) — 25 °C below the carbon-fibre grade[2][8]
Bed temperature°C60 (Proto-pasta)[1]95 ± 10 (Prusament)[2]
Enclosure / chamber requirement1–5Open frame is fine[1]Enclosure recommended — Simplify3D lists an enclosure as a hardware requirement and Polymaker advises one below 70 °C ambient to stop warping and cracking[9][10]
Part cooling fanNot documentedOff — Prusa runs 0 % except 100 % on bridges[2]
Maximum volumetric flow (mm³/s; see test conditions)mm³/s1.6–2.4 at Proto-pasta's 20–30 mm/s on a 0.4 mm nozzle at 0.2 mm layer[1]4 at Prusa's 50 mm/s cap on a 0.4 mm nozzle at 0.2 mm layer[2][11]
Warping tendency1–5Not documentedHigh — enclosure needed for reliable large parts; Prusa recommends a brim[2]
Bed-adhesion difficulty1–5Not documentedVery difficult — special plates or slurry required[2]
Overall printing difficulty1–5Intermediate — dry filament and a tuned profile; slow, and brittle in filament form[1]Advanced — enclosure, hardware upgrades, tuning; hardened nozzle mandatory[2]
Extruder requirementProto-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]Prusa states a hardened nozzle is necessary and recommends a brim[2]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass acceptable; hardened steel for volume work[1]Hardened steel required[2]
Abrasiveness1–5Moderately abrasive — metal fill[1]Highly abrasive — standard GF composite[2]
Nozzle clog risk1–5Moderate — 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]Moderate — needs dry filament and a clean nozzle; Prusa lists higher risk of nozzle clogging for glass-filled composites[13]
Hotend requirementProto-pasta recommends a wear-resistant or larger nozzle for longer service intervals[1]Not documented
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Not documentedLow (0.1–0.3 %) — 0.11 % at both 24 h and 7 days, higher than the carbon-fibre grade's 0.04 % but still very low[2][8]
Equilibrium moisture content at ~50 % RH%Not documented0.11 after 24 h and 0.11 after 7 days at 24 °C / 22 % RH (Prusa Polymers)[2]
Effect of moisture on strengthPolymaker rates PLA low-sensitivity and publishes no dry-versus-conditioned figures; absorbed water flashes to steam and shows as bubbling and poor layer adhesion[14]Not applicable in practice at 0.11 % equilibrium uptake[2]
Storage requirementNot documentedNo special storage needed[2]
Mechanical Properties
Tensile strength (XY)MPaNot documented46.6 ± 1.3 filament tensile yield (Prusament, ISO 527) — more than double the carbon-fibre grade's 21[2][8]
Charpy impact, notchedkJ/m²Not documented7.9 ± 0.4 printed horizontal and 9.9 ± 0.8 printed vertical XZ (ISO 179-1, notched)[2]
Brittleness1–5Brittle — Proto-pasta describes the filament as more brittle than standard PLA and needing extra care in handling[1]Moderate[2]
Hardness (scale-specific)Shore A / Shore D / RockwellNot documentedRockwell R102 (and M95) on extruded unfilled PP stock (ASTM D785); no figure is published for a glass-fibre PP filament[15]
Elasticity / flexibility1–5Rigid[1]Rigid[2]
Thermal Properties
HDT at 0.45 MPa°CNot documented138.3 (ISO 75, 0.45 MPa)[2]
HDT at 1.8 MPa°CNot documented112.6 (ISO 75, 1.8 MPa)[2]
Environment & Chemical
Outdoor durabilityDeliberately rustable — Proto-pasta markets the iron content as oxidising when exposed to moisture[1]Not documented
Chemical resistanceNot documentedExcellent against acids, alkalis and most solvents[10]
Water / humidity resistance in service1–5Not documentedExcellent — essentially unaffected[2]
Electrical & ESD propertiesFerromagnetic: Proto-pasta states it responds to magnets and behaves similarly to pure iron[1]Not documented
Health & Safety
Fume toxicity1–5Low hazard — minimal VOC and particle emission; none of these materials was in the chamber study[16]Low hazard — minimal VOC and particle emission. Inferred: no polyolefin was among the nine filaments in the Azimi chamber study, so this is a family-level judgement rather than a measurement[16]
Ventilation / filtration requirement1–5Open a window / occasional ventilation[16]Open a window / occasional ventilation. Inferred — no polyolefin was measured in the chamber study[16]
Dust & fibre handling hazardNot documentedGlass fibre is bound in the matrix; avoid inhaling sanding dust[2]
Post-Processing
Sanding & machiningPolishing and deliberate rusting are the intended finishes[1]Not documented
Solvents & Solubility
Soluble inChloroform dissolves the PLA matrix and leaves the iron powder behind; laboratory reagent, not workshop stock.[17][1]None at room temperature; chloroform dissolves the matrix at 60 °C and xylene at about 118 °C, leaving the fibre.[18][19]
Softened or crazed byAcetone and ethyl acetate plasticise the matrix rather than dissolving it; water attacks the exposed iron.[17][1]Xylene, decalin, CCl4 and chlorobenzene are heavily absorbed at 20 °C; oleum, chlorosulphonic acid and bromine destroy it.[18]
Solvent welding & smoothing agentNone — PLA has no workshop-safe solvent, and the iron loading blocks the surface flow smoothing needs.[17]None — nothing softens PP at room temperature, so joints have to be welded thermally rather than chemically.[18]

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. Magnetic Iron PLA — product page and technical data Proto-pasta · 2026-08 · tds
  2. Prusament PP Glass Fiber Technical Datasheet v1.0 Prusa Polymers · 2024-11 · tds
  3. Prusament PP Glass Fiber — material page Prusa Polymers · 2026-08 · doc
  4. Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
  5. BASF Ultrafuse PP GF30 Black 2.85 mm 2.200 g igo3d · 2026-08 · vendor
  6. BCN3D PP GF30 Black 2.85 mm 700 g igo3d · 2026-08 · vendor
  7. Prusa Prusament PP Glass Fiber Natural (NFC), 1.75 mm / 850 g 3DJAKE · 2026-08 · vendor
  8. Prusament PP Carbon Fiber Technical Datasheet v1.0 Prusa Polymers · 2024-11 · tds
  9. Polypropylene — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  10. PP — material basics Polymaker Wiki · 2026-08 · doc
  11. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  12. Composite materials with metal or wood particles Prusa Knowledge Base · 2026-08 · doc
  13. Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
  14. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  15. TECAFINE PP natural — stock shape properties Ensinger · 2026-08 · tds
  16. 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
  17. Solubility Study of Ingeo Biopolymer Grades in Common Organic Solvents (NWPD003) NatureWorks · 2019-10 · tds
  18. Pro-fax and Moplen polypropylene — Chemical Resistance Guide (20, 60 and 100 °C) LyondellBasell · 2026-08 · tds
  19. US 5,278,282 Polymer recycling by selective dissolution — xylene dissolution temperatures Nauman & Lynch, Rensselaer Polytechnic Institute · 1994-01 · paper