3D Printing InfoFilament comparison
Magnetic vs PVB
Compare printing settings, strength, heat resistance, dated prices and sources.
2 selected · all documented properties
| Property | Magnetic filamentSPECIALTY | PVBSPECIALTY |
|---|---|---|
| Market snapshot | ||
| Listing priceUSD/kg; dated snapshots | $64.99/kg median; $64.99–$64.99/kg across 1 dated product listings | $66.65/kg median; $49.32–$79.98/kg across 3 dated product listings |
| Identity & Market | ||
| Base polymer / chemistry | PLA loaded with ferromagnetic iron powder, so printed parts respond to magnets[1] | Polyvinyl butyral — a printable thermoplastic whose surface can be smoothed with isopropyl alcohol instead of a hot solvent[2] |
| Densityg/cm³ | About 1.85 (Proto-pasta manufacturer figure) — 1.5× standard PLA[1] | 1.10 (Polymaker PolySmooth, ISO 1183); Prusament PVB 1.10[2][3] |
| Typical priceUSD/kg | 1 kg spools cluster near 65[4] | 1 kg-equivalent spools cluster near 80[5][6] |
| Price range across brandsUSD/kg | 64–70 across formats; 1 kg spool 65, 500 g 70, 2 kg 70[4] | 49–102 across brands; Polymaker PolySmooth 49 at 750 g, Prusament PVB 80–102 at 500 g[5][6] |
| Market availability1–5 | Niche, a handful of specialist brands[4] | Available from several mainstream brands[5][6] |
| Spool sizes & diameters | 1.75 and 2.85 mm; 0.1, 0.5, 1 and 2 kg spools[4] | 1.75 and 2.85 mm; 0.5 and 0.75 kg spools[5][6] |
| Typical applications | Sensor targets, magnetic fixtures, and props that need to stick to a magnet or rust deliberately[1] | Display models and light guides where a layer-free surface matters more than strength[2] |
| Diameter tolerance± mm | Not documented | +/- 0.03 (Prusament PVB)[3] |
| Printing Parameters | ||
| Nozzle temperature°C | 192 (Proto-pasta)[1] | 215 +/- 10 (Prusament PVB)[3] |
| Bed temperature°C | 60 (Proto-pasta)[1] | 75 +/- 5 (Prusament PVB)[3] |
| Enclosure / chamber requirement1–5 | Open frame is fine[1] | Open frame is fine[2] |
| Part cooling fan | Not documented | 100 % part cooling (Prusament PVB)[3] |
| Bed surface & adhesion aid | Not documented | Smooth PEI sheet or satin sheet; Prusa states a brim is not generally necessary[3] |
| 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] | Not documented |
| Overall printing difficulty1–5 | Intermediate — dry filament and a tuned profile; slow, and brittle in filament form[1] | Easy — minor profile tuning; it prints close to PLA[2] |
| 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[2] |
| Abrasiveness1–5 | Moderately abrasive — metal fill[1] | Non-abrasive[2] |
| 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[7] | Moderate — needs dry filament and a clean nozzle; Prusa calls PVB very prone to absorbing moisture and requires a 60 °C, 4 h dry before every print[8][9] |
| Hotend requirement | Proto-pasta recommends a wear-resistant or larger nozzle for longer service intervals[1] | Not documented |
| Moisture Behaviour | ||
| Moisture absorption (hygroscopicity)1–5 | Not documented | Very high (>2 %) — 2.36 % equilibrium water absorption (Polymaker PolySmooth), above every PLA and PETG grade here[2] |
| Equilibrium moisture content at ~50 % RH% | Not documented | 2.36 equilibrium water absorption (Polymaker PolySmooth); 2.09 for PolyCast; Prusament PVB takes up 0.18 in 24 h and 0.35 in 7 days at 24 °C and 22 % RH[2][10][3] |
| Drying temperature & time | Not documented | Maximum 60 °C for 4-8 h depending on how wet the filament is (Prusament PVB)[3] |
| 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[9] | Polymaker publishes no dry-versus-conditioned figures; at 2.36 % equilibrium uptake the material has to be kept dry to print cleanly[2][9] |
| Storage requirement | Not documented | Sealed with desiccant[9] |
| Mechanical Properties | ||
| Tensile strength (XY)MPa | Not documented | 51.8 ± 0.7 printed XY, ISO 527 (PolySmooth); 53.2 ± 1.1 for PolyCast; Prusament PVB gives 50 +/- 5 at yield printed horizontal (ISO 527-1) and 57 +/- 1 on the filament (ISO 527)[2][10][3] |
| Young's modulusMPa | Not documented | 2199 ± 43 printed XY and 2010 ± 69 printed Z, ISO 527 (PolySmooth); Prusament PVB gives 1700 +/- 100 in both print directions (ISO 527-1)[2][3] |
| Elongation at break% | Not documented | 5.7 ± 0.5 printed XY, ISO 527 (PolyCast)[10] |
| Flexural strengthMPa | Not documented | 72 +/- 1 printed horizontal and 73 +/- 3 printed vertical, ISO 178 (Prusament PVB)[3] |
| Flexural modulusMPa | Not documented | 2233 ± 106 printed XY, ISO 178 (PolyCast); Prusament PVB gives 2200 +/- 100 horizontal and 2300 +/- 100 vertical (ISO 178)[10][3] |
| Charpy impact, notchedkJ/m² | Not documented | 7 +/- 1 printed horizontal and 10 +/- 1 printed vertical, ISO 179-1 notched (Prusament PVB)[3] |
| Other impact data | Not documented | Charpy unnotched 55 +/- 7 printed horizontal and 59 +/- 12 printed vertical (Prusament PVB, ISO 179-1)[3] |
| Layer adhesion / Z tensileMPa | Not documented | 26.3 ± 2.1 printed Z, ISO 527 (PolyCast); Prusament PVB gives 49 +/- 5 at yield printed vertical (ISO 527-1) and 9 +/- 1 on Prusa's interlayer adhesion test[10][3] |
| Brittleness1–5 | Brittle — 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 / Rockwell | Not documented | Shore D 77 (Prusa Polymers method)[3] |
| Elasticity / flexibility1–5 | Rigid[1] | Rigid[2] |
| Z strength as % of XY% | Not documented | 98 (Prusament PVB, printed vertical against horizontal tensile yield, ISO 527-1: 49 +/- 5 against 50 +/- 5) — the most isotropic printed material in this dataset[3] |
| Thermal Properties | ||
| HDT at 0.45 MPa°C | Not documented | 68 (PolySmooth) and 67 (PolyCast), ISO 75 at 0.45 MPa; Prusament PVB 63 (ISO 75 at 0.45 MPa)[2][10][3] |
| HDT at 1.8 MPa°C | Not documented | 66 (PolySmooth) and 53 (PolyCast), ISO 75 at 1.8 MPa; Prusament PVB 58 (ISO 75 at 1.8 MPa)[2][10][3] |
| Glass transition (Tg)°C | Not documented | 70 (DSC) for both PolySmooth and PolyCast[2][10] |
| Melting point / Vicat°C | Not documented | Amorphous — no melting point; Vicat 70 (PolySmooth) and 67 (PolyCast), ISO 306[2][10] |
| Environment & Chemical | ||
| Outdoor durability | Deliberately rustable — Proto-pasta markets the iron content as oxidising when exposed to moisture[1] | Not documented |
| Electrical & ESD properties | Ferromagnetic: Proto-pasta states it responds to magnets and behaves similarly to pure iron[1] | Not documented |
| Health & Safety | ||
| Fume toxicity1–5 | Low hazard — minimal VOC and particle emission; none of these materials was in the chamber study[11] | Low hazard — minimal VOC and particle emission; none of these materials was in the chamber study[11] |
| Ventilation / filtration requirement1–5 | Open a window / occasional ventilation[11] | Open a window / occasional ventilation[11] |
| Post-Processing | ||
| Sanding & machining | Polishing and deliberate rusting are the intended finishes[1] | Not documented |
| Vapour / chemical smoothing | Not documented | Isopropyl alcohol vapour smoothing is the point of the material — Polymaker markets PolySmooth for hands-free post-processing to a layer-free surface[2] |
| Support material pairing | Not documented | PolyDissolve S1 is rated for PVB (Polymaker)[12] |
| Dimensional accuracy & detail | Not documented | PolyCast is the investment-casting variant of the same chemistry — it burns out cleanly rather than being smoothed[10] |
| Solvents & Solubility | ||
| Soluble in | Chloroform dissolves the PLA matrix and leaves the iron powder behind; laboratory reagent, not workshop stock.[13][1] | Isopropyl alcohol dissolves it; Prusa describes PVB as soluble only in IPA, and it is not water-soluble.[8] |
| Softened or crazed by | Acetone and ethyl acetate plasticise the matrix rather than dissolving it; water attacks the exposed iron.[13][1] | Not documented |
| Solvent welding & smoothing agent | None — PLA has no workshop-safe solvent, and the iron loading blocks the surface flow smoothing needs.[13] | Isopropyl alcohol: brushed or sprayed on for speed, or several hours in IPA vapour for a glass-like surface.[14][8] |
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
- PolySmooth Technical Data Sheet V5.4 Polymaker · 2024-11 · tds
- Prusament PVB Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
- Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
- Polymaker product catalogue Polymaker · 2026-08 · vendor
- Printed Solid product catalogue Printed Solid · 2026-08 · vendor
- Composite materials with metal or wood particles Prusa Knowledge Base · 2026-08 · doc
- Prusament PVB — material page Prusa Polymers · 2026-08 · tds
- Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
- PolyCast Technical Data Sheet V5.4 Polymaker · 2024-11 · 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
- PolyDissolve S1 Technical Data Sheet V5.4 Polymaker · 2024-11 · tds
- Solubility Study of Ingeo Biopolymer Grades in Common Organic Solvents (NWPD003) NatureWorks · 2019-10 · tds
- Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc