MarkForged Printing Materials - An In-Depth Review


MarkForged Mark One Printing Filament Overview


MarkForged Mark One Printing Materials Overview

We have now been playing with the MarkForged Mark one (professional kit) for well over 6 months so we thought it was time to give a real-life, no holds barred review of our experience with the Mark One printing materials so far.

We’d like to start out by saying we are constantly impressed by the simplicity of the Mark One printer and the accompanying Eiger software. They work beautifully together. Creating and fine-tuning 3D prints has been an easy, wonderful experience.

The three materials (aside from the Nylon base) that the Mark One can print are Carbon Fiber, Kevlar, and Fiberglass. Each has its strengths and weaknesses that we will discuss in this article.


MarkForged Nylon printed 3D part

Nylon is the base material for all of the MarkForged 3D parts printed using the Mark One. Nylon itself is great for making strong, durable 3D printed parts. Using the Mark One, you can choose the density and fill shape when using Nylon. Fill shapes include triangle (seen above), rectangle and hexagonal. Fill density ranges from 0 to 100% depending on the strength needed. We find there isn't a lot of difference in fills over 50% which is our default setting.

Nylon Filament Strength Properties

  • Tensile Strength (MPa) ASTM D3039: 56
  • Tensile Modulus (GPa) ASTM D3039: 0.38
  • Tensile Strain at Break (%) ASTM D3039: >50
  • Flexural Strength (MPa) ASTM D790: No Break
  • Flexural Modulus (GPa) ASTM D790: 0.4
  • Flexural Strain at Break (%) ASTM D790: No Break
  • Compressive Strength (MPa) ASTM D6641: N/A
  • Compressive Modulus (GPa) ASTM D6641: N/A
  • Compressive Strain at Break (%) ASTM D6641 N/A
  • Heat Deflection Temperature (C°) ASTM D648 44-50

    Carbon Fiber


    MarkForged Carbon Fiber printed 3D part

    Let’s start with the good. Carbon fiber printed 3D parts are strong. Really strong. Our typical way to show this is by handing customers a Nylon printed part and ask them to bend it. The response is usually, “that is really strong”. We then hand them the same part infused with just a few layers of continuous carbon fiber strands and they are blown away.

    Carbon fiber is by far the most rigid of the materials which means it is also the most difficult to work with. We have had minor feeding issues using Carbon Fiber and nozzles tend to become clogged after a print is completed as the printer cools down. This is an easy fix by simply heating the nozzle and clearing the jam, but we have not found this issue with Fiberglass or Kevlar.

    Overall, we have found that Carbon Fiber is worth the extra work it can sometimes cause due to its extremely impressive strength, unique to anything on the market today.

    Carbon Fiber Filament Strength Properties

    • Tensile Strength (MPa) ASTM D3039: 700
    • Tensile Modulus (GPa) ASTM D3039: 50
    • Tensile Strain at Break (%) ASTM D3039: 1.5
    • Flexural Strength (MPa) ASTM D790: 470
    • Flexural Modulus (GPa) ASTM D790: 48
    • Flexural Strain at Break (%) ASTM D790: 1.2
    • Compressive Strength (MPa) ASTM D6641: 320
    • Compressive Modulus (GPa) ASTM D6641: 50
    • Compressive Strain at Break (%) ASTM D6641: 0.7
    • Heat Deflection Temperature (C°) ASTM D648: 105


    MarkForged Kevlar printed 3D part

    Kevlar printing with the Mark One printer (this author’s personal favorite) is strong, durable and easy to use. Is it is strong as Carbon Fiber? No, but not all applications require that level of stiffness and strength. Kevlar feeds effortlessly through the machine and we are yet to have a jam when using this material.

    Kevlar does boast the best flexibility and abrasion resistance of all three materials. This lends itself well to applications where “bend” is not a bad word (think custom shoe insoles) and friction or wear is a concern.

    Kevlar Fiber Filament Strength Properties

    • Tensile Strength (MPa) ASTM D3039: 610
    • Tensile Modulus (GPa) ASTM D3039: 26
    • Tensile Strain at Break (%) ASTM D3039: 5.5
    • Flexural Strength (MPa) ASTM D790: 190
    • Flexural Modulus (GPa) ASTM D790: 24
    • Flexural Strain at Break (%) ASTM D790: 2.1
    • Compressive Strength (MPa) ASTM D6641: 97
    • Compressive Modulus (GPa) ASTM D6641: 26
    • Compressive Strain at Break (%) ASTM D6641: 1.5
    • Heat Deflection Temperature (C°) ASTM D648: 105


    MarkForged Fiberglass printed 3D part

    Fiberglass doesn’t get the credit it deserves with the Mark One printer, maybe because saying you have a Carbon Fiber or Kevlar 3D part sounds so cool. Fiberglass has a number of advantages and definitely fills a need in this family of 3D printing materials.

    First, Fiberglass is the least expensive of the three. This allows you to make strong parts for less. Fiberglass is nearly as strong as Carbon Fiber, however, 40% more flexible. It also comes with 2X the weight of Carbon Fiber so large parts that require absolute minimal weight probably aren’t for Fiberglass.

    As far as use, Fiberglass prints just as nicely as Kevlar with no jams to date (knock-on-wood) and is easy to feed through the Mark One printer. Finally, if you decide to go with the Standard Mark One printer instead of the Professional kit (Kevlar only works with the Professional printer), Fiberglass still provides a nice compliment to Carbon Fiber printing.

    Fiberglass Fiber Filament Strength Properties

    • Tensile Strength (MPa) ASTM D3039: 590
    • Tensile Modulus (GPa) ASTM D3039: 20
    • Tensile Strain at Break (%) ASTM D3039: 5.5
    • Flexural Strength (MPa) ASTM D790: 310
    • Flexural Modulus (GPa) ASTM D790: 21
    • Flexural Strain at Break (%) ASTM D790: 2.1
    • Compressive Strength (MPa) ASTM D6641: 140
    • Compressive Modulus (GPa) ASTM D6641: 20
    • Compressive Strain at Break (%) ASTM D6641: 0.7
    • Heat Deflection Temperature (C°) ASTM D648: 105


    So there it is, our experience printing using Carbon Fiber, Kevlar and Fiberglass on the Mark One Professional printer. For in-depth specs on the strengths of each of these materials, please take a look at this material data sheet (link).

For any questions about the MarkForged 3D printer or any of these materials, please feel free to contact one of our experts to get all of your questions answered.


    Dimensions and construction of test specimens
    • Test plaques used in this data are fiber reinforced unidirectionally (0° Plies).
    • Tensile test specimens: 9.8 in (L) x 0.5 in (H) x 0.048 in (W) (CF composites), 9.8 in (L) x 0.5 in (H) x 0.08 in (W) (GF and aramid composites),
    • Compressive test specimens: 5.5 in (L) x 0.5 in (H) x 0.085 in (W) (CF composites), 5.5 in (L) x 0.5 in (H) x 0.12 in (W) (aramid and GF composites)
    • Flexural test specimens: 3-pt. Bending, 4.5 in (L) x 0.4 in (W) x 0.12 in (H)
    • Heat-deflection temperature at 0.45 MPa, 66 psi (ASTM D648-07 Method B)

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    • Dustin Heigl
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