Working with Filamet™ and Spool Placement

Due to its high metal content, Filamet™ will inherently break more easily than standard PLA. Following these instructions will make Filamet™ easy to use.

  • Place the spool so that pull and friction are reduced as much as possible. The filament should come off the spool straight into the feeder. for Direct Drive, this means you simply hang the spool right above the printer. for Bowden fed printers, this means placing the spool next to or under the feeder.

  • Use a FilaWarmer to ease the path from spool to printer.

    • The metal particles in Filamet™ are surrounded by plastic. This plastic keeps the memory of its shape on the spool. As Filamet™ passes through the warmer, the memory of the Filamet™ is reset and prints with ease. This effect lasts about 24 hours.

    • Caution! Heating the entire spool at once will cause the filament to become extremely brittle. It’s important to heat only the single strand as it goes into the printer.

  • To report any issues with Filamet™ after trying a FilaWarmer, please contact


FilaWarmer Setup

The FilaWarmer comes pre-programmed to 60°C - perfect for Stainless Steel 316L Filamet™.
For Bronze and Copper, adjust the temperature to 45°C.

Hang the FilaWarmer so that the top of the warming tube is at the same level as the spool center hole. Purchase a FilaWarmer in our Online Store.

Recommended Nozzle

Copper, Bronze, Stainless Steel 316L, Aluminum 6061 and Titanium 64-5 Filamet™, use a 0.6mm or larger standard stainless steel nozzle.

High Carbon Iron Filamet™, use a 0.8mm or larger hardened nozzle.

Printer Heat Settings

205-215°C (401-419°F)

Set print bed to 50°C (122°F) (optional)

Print Bed Preparation

With a glass build plate, apply a layer of glue using a glue stick. To remove the print, use water and a razor blade.

With a PEI, aluminum, or other non glass build plate, apply a layer of blue painters tape. For easier removal of prints, heat the print bed before removing the print.

Note: Do not print Filamet™ directly onto PEI. Prints will weld to the print bed.

Print Speed

30mm/sec (1800mm/min) to start.

Layer Height

Many slicers lay down an extra wide first layer to get good adhesion to the bed.

This is not a problem unless the first layer is very short. With traditional PLA, it will simply squeeze out at the sides. Filamet™ is more viscous which slows this process. If the nozzle seems clogged, it may be that the nozzle is too close to the build plate on the first layer. Once dialed in, some users are printing down to a layer height of 0.1mm.


Printing Tips

  • Filamet™ prints just like any other PLA 3D printing filament, with one exception... start slow. Rushed prints are the most common cause of rough prints.

  • With experience, prints can be faster, but for a quick win on a first try, start at about 30mm/sec (1800mm/min). Increase to normal speed as experience is gained.

  • Don’t be afraid to turn up your flow rate. Filamet™ prints different from other filaments and requires a greater flow to fill in all the gaps for a perfect, high density part.

    • Infill should overlap perimeters to ensure a solid part.

  • If prints fail from jams after the first layer, make sure the temperature on your printer is accurate.

TVF’s Simplify3D FFF profiles: Use as a base for starting to use Filamet™.



Sanding and polishing our metal filaments
With heat, our metal filament becomes clay-like. It can be carved, re-sculpted, pieces can be added and seams smoothed.

How to avoid melting when sanding metal filament
Important! Constant movement to different areas of the part is necessary when sanding to avoid unintentional melting. Experimenting is worthwhile.

Needle file:  To make print lines vanish, sand the surface even. The loose particles from sanding are smashed into the print line gaps with the heat from the friction, fixing them in place. This step is complete once the entire print’s surface is smooth and even.

Sandpaper or 3M Radial Disc:  Start with 120 grit sandpaper or 80 grit 3M Radial Disc, and go over every part of the print. The matte surface will become shiny as finer grits are used. Complete the entire surface of the print before moving to the next grit. The Virtual Foundry recommends using 4 grits with 3M and 6 or 7 grits with sandpaper. A nice shine can be achieved with less, but the mirror shine comes closer to the 7, ending around 3000 grit. After sanding, rub the print down with some flannel or a sunshine cloth to clean off loose particles. A mirror shine should be evident at this phase, even before the last step.

Sewn Buff and Zam:  Place sewn buff on a rotary tool, then liberally apply zam to the buff and to your print. The print will melt if it gets too hot, so it is critical to keep the buffer moving and continue to apply zam liberally. It may be useful to practice this step on a simple print or a “failed print.”


Sintering in an Open Environment
(Copper and Bronze Filamet™ Only)

Items Needed:  

Kiln / Sintering Furnace
Refractory Container (Crucible)
Sintering Refractory Ballast - AI₂O₃
Granular coconut shell carbon
Brass brush

Crucible Preparation:

  1. Place a 10mm layer of refractory (AI₂O₃) on the bottom of a stainless steel crucible.

  2. Position the part(s) avoiding contact with other parts or the walls of the crucible.

  3. Cover the parts completely with a minimum of 10mm of refractory (AI₂O₃). Tap the crucible gently to compact the refractory around each part.

  4. Place a 10mm layer of granular coconut shell carbon on top of the refractory and place a suitable stainless steel cover over the crucible.

Sintering Program:

  1. Phase 1: Ramp Kiln/Furnace Temperature by 120°C per hour up to 815°C (Bronze) or 1000°C (Copper). Do not hold.

  2. Phase 2: Ramp Kiln Temperature by 25°C per hour to sinter temperature; 870°C (Bronze) or 1050°C (Copper) and hold at sinter temp for 1.5 hours for very small parts (15g or less) or up to 5.0 hours or more for larger parts (300g+).

  3. NOTE – Sinter temperature and hold times may vary based on Kiln model, part density and design.

  4. Let the crucible cool fully (less than 50°C) before handling the sintered part.

Post Sintering:

  1. Use a brass brush to clean the surface of the part under running water.

  2. Polish the part using a Dremel or in a tumbler using a suitable polishing media, water and detergent (dish soap).

Technical Support:

This open atmosphere sintering process was developed exclusively by Sapphire3D Inc. Sapphire3D Inc. is a Reseller of The Virtual Foundry Materials. For Sintering Services and Technical Support, contact Sapphire3D, Inc. directly at:


Sintering in a Vacuum
or Inert Environment
(All Materials)

Items Needed:  
Sintering Furnace (Options Here)
Refractory Container (Crucible)
Sintering Refractory Ballast:
Powdered Graphite

Prep:  Place the object in the refractory, ensuring the entire print and all surfaces are completely covered and any protruding areas are fully supported. The print must be fully surrounded by the refractory. Ensure that at least 10mm of refractory insulates the print from the walls of the crucible.

Fire:  Place the Crucible in the furnace and begin the firing cycle.

Firing Cycle:

1. Start at room temperature.

2. Over the course of 200 minutes, ramp temp to 205°C (401°F). Do not hold.

3. Over the course of 180 minutes, ramp temp to 400°C (752°F). Do not hold.

4. For Copper: Over the course of 180 minutes, ramp temp to 1000°C (1832°F) and hold for 440 minutes.

For Bronze: Over the course of 180 minutes, ramp temp to 815°C (1499°F) and hold for 440 minutes.

For Stainless Steel 316L: Over the course of 180 minutes, ramp temp to 1225°C (2237°F) and hold for 240 minutes.

For High Carbon Iron: Over the course of 180 minutes, ramp temp to 1120°C (2048°F) and hold for 400 minutes.

5. End cycle and let furnace cool to ambient temp until Crucible can be removed by hand.

 *Note: Every situation is different and you may need to modify your sintering times and temperatures based on your application and use of our materials. These are just general guidelines.*

This process takes around 12 hours and has been tested on prints up to 200g.

For first trials, plan for 15-20% shrinkage of the part overall through the sintering process.

Tip:  The mechanical properties of the final product are directly related to how long the print is held at the sintering temperature. If the end product is powdery and brittle, it’s under sintered. If the print looks like old wrinkled fruit, it’s over-sintered.

Print is ready for finish work!

Filament  Sinter Temp
Bronze Filamet™  815°C (1499°F)
Copper Filamet™  1000°C (1832°F)
Stainless Steel 316L Filamet™  1200°C (2192°F)
High Carbon Iron Filamet™  1250-1350°C (2282-2462°F)
Aluminum 6061 Filamet™  555°C (1031°F)
R3DS Tungsten  1200-1400°C (2192-2552°F)


Furnaces used to sinter objects printed with Filamet™ should meet the requirements below:

Filamet™  Max Temp  Atmosphere  MBP Needed?  Programmable?
Copper & Bronze  1100°C (2012°F)  Open  Yes  Yes
Copper & Bronze  1100°C (2012°F)  Vacuum or Inert  No  Yes
SS316L  1400°C (2552°F)  Vacuum or Inert  No  Yes

Note:  Furnaces can vary in temperature by 37.8°C (100°F) from the furnace readout which can adversely affect results. Test furnace temperature with an independent thermometer.

When a vacuum or inert environment furnace is used, no Magic Black Powder is needed. Instead, use a suitable refractory to support the print's shape. TVF recommends powdered graphite (available in our Online Store).

See the Sintering Furnace Information page for a purchasing resource.


How should I place Filamet™ when I am printing with it?
Place the spool so that pull and friction are reduced as much as possible. The filament should come off the spool straight into the feeder. for Direct Drive, this means you simply hang the spool right above the printer. For Bowden fed printers, this means placing the spool next to or under the feeder.

How strong is Filamet™?
While Filamet™ isn’t as strong as standard PLA (because of the very high metal content), it is still sturdy. Reducing friction on the Filamet™ as it's pulled into the printer is key.

What kind of printer does Filamet™ work on?
Filamet™ works in any Fused Filament Fabrication (FFF) printer. If the printer prints with standard PLA, it will print with Filamet™. If your printer requires that you only use materials from the printer manufacturer, you may not be able to print with Filamet™.

What is the Metal Content of Filamet™?

How is density calculated?
Weight divided by volume.

Is Filamet™ Conductive?
While in its printable spool form, Filamet™ has a PLA binder. Through sintering, the PLA binder is burned off and the remaining object has the same conductive properties of whatever metal it is.

What are the print settings for Filamet™?
Printer settings and sinter firing schedule can both be found on the Use Instructions page and printed instructions are included with every order.

I want to sinter a print. Where should I start?
The best way to learn the sinter process is to print the swirly cone model and then follow the sintering instructions on the Use Instructions page which are set for this size model. Sintering times vary by the size of the print.


Where can I find Safety Data Sheets (SDS) for Filamet™?
All SDS are on this page.

Are you going to have more printable metals?
The Virtual Foundry is consistently working on expanding available products. Keep watching this website, our Facebook page and our LinkedIn page for new material announcements. Looking for custom development? Let us know!

What makes Filamet™ special?
Filamet™ makes metal printing available to anyone with a desktop 3D printer - no need to purchase a costly printer to print with metal.

What kind of kiln do I need?
Mainly, the kiln needs to be programmable. The Virtual Foundry offers the same furnace for sale that we use in-house. Check it out here.

What is the mix ratio for Magic Black Powder (MBP)?
As a starting point, consider a ratio of 1 to 2 with 1 cup of water to 2 cups of MBP. This may be a bit on the dry side in which case a bit more water should be added. The goal of the mixture is a bit runny but not like water. A layer of MBP will be painted on to the print to create a mold that holds the object's shape while firing. Be sure to apply to all the detail of the print - cracks, crevasses, etc. While this layer is being applied, the remainder of the MBP mixture will begin setting. Starting with a thinner mixture will offer more time for this process. It's important to have that first layer fully applied and the object into the remaining MBP mixture when the mixture is just barely thick enough to suspend the object. If the mixture is too thick, air pockets may form and create deformities in your fired object.
Note: Metal cylinders work best as the firing vessel.

How should I store Filamet™?
Filamet™ does not appreciate being exposed to air for weeks. When not in use, store Filamet™ in a sealed plastic bag with the desiccant pack included with the product.

I need help! What do I do?
Send us an email. We’d love to help!

Where is the link for the swirly cone model?
Here and at the bottom of every page of this website.

Where can I buy Filamet™?
You can buy Filamet™ on our online store.

Do you ship to the UK?
Yes we do! We ship worldwide!

What nozzle size should I use?
Start with a 0.8mm with High Carbon Iron Filamet™ and a 0.6mm for all other filaments.

What should my nozzle be made of?
Brass works to start, but we recommend stainless steel or hardened steel. High Carbon Iron Filamet™ requires a hardened steel nozzle.

The applications for Filamet™ are endless, everything from jewelry to blocking radiation.

Please share your experience and applications on Facebook.