Prusa XL and Silicone Printing: Industrial Technology on a Desktop Printer

The Original Prusa XL has long positioned itself as a large-format, modular FDM printer with interchangeable toolheads. In 2026, however, it received an upgrade that moves it from conventional plastic printing into the world of truly industrial materials: a new Silicone Printing Toolhead, developed by the startup Filament2 exclusively for the Prusa XL.

This plug-and-play toolhead enables the printing of two-component, temperature-resistant silicone and other similar liquid materials. What does this mean in practice for Prusa XL users, how does silicone printing work, and what applications does it make sense for? Let’s take a detailed look.

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Why Printing Real Silicone Is So Interesting

Until now, most “ible” parts on desktop printers have been printed from TPU / TPE filaments. Although these are ible, they:

• are generally not as resistant to high temperatures as silicone,
• cope less well with chemical exposure and aging,
• often have poorer tensile elasticity (material memory, returning to the original shape).

By contrast, silicone elastomers (especially two-component RTV / LSR systems):

• normally withstand continuous temperatures of 150–200 °C and even higher temperatures for short periods,
• are chemically resistant to oils, lubricants, water, and a wide range of chemicals,
• have excellent elasticity and damping properties,
• and are used industrially for seals, O-rings, silicone molds, medical devices and other applications.(en.wikipedia.org)

The possibility of 3D printing real silicone therefore opens the door to producing parts that were previously practically unattainable through desktop 3D printing – you either had to move to very expensive industrial LAM systems or use indirect methods (printing a mold and casting silicone).(innovatiq.com)

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What Exactly Is the Filament2 Silicone Toolhead for the Prusa XL

Prusa Research officially introduced the Silicone Printing Toolhead for the Original Prusa XL as one of the key elements expanding the XL tool ecosystem.(blog.prusa3d.com)

Key features from the user’s perspective:

• Plug-and-play integration into the XL platform – the toolhead behaves like another “tool” and connects to the existing tool-changing system.
• Two-component dispensing: the head has separate channels for the two components of the silicone (A and B), which lead to a static mixing nozzle.
• Precise dispensing and mixing: the ratio of both components is controlled to achieve proper curing and mechanical properties. A similar principle is used by industrial 2K dispensing and printing heads for silicone and epoxy.(viscotec.com)
• Designed for high-viscosity liquid materials – primarily two-component silicone, but conceptually also other reactive systems (polyurethane, epoxy, etc.), if they are compatible with the head.

Unlike a conventional FDM extruder, here you do not print filament, but controlled extrusion of two components of a liquid material into the nozzle, where mixing takes place, followed by depositing the material layer by layer.

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How Two-Component Silicone 3D Printing Works

1. Two-Component System (A+B)

Standard RTV2 / LSR silicones are two-component systems that begin to cure chemically after mixing. For printing to be stable and repeatable, it is necessary to:

• precisely control the mixing ratio (e.g. 1:1 or 10:1),
• ensure uniform mixing across the entire cross-section,
• control the pot life so that the material does not solidify in the nozzle.

This is precisely what the mixing nozzle is for: the two components are extruded separately and meet only in the static mixer in the nozzle, where a homogeneous mixture is created.(lynxter.fr)

2. Material Deposition and Curing

The extruded silicone is relatively viscous – it holds its shape and enables layering upward. Depending on the mixture used, it may undergo:

• RTV condensation (curing at room temperature),
• or faster curing at elevated temperatures in the print area or an oven.

This makes it possible to print:

• fine sealing edges and profiles,
• hollow structures with controlled elasticity,
• thin-walled membranes and spring geometries.

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Which Projects Make Sense for Silicone Printing on the Prusa XL

1. Seals, O-Rings, and Industrial Parts

One of the most natural applications is the production of seals and ible joints:

• complex-shaped seals for machine and equipment prototypes,
• custom O-rings where standard sizes are insufficient,
• vibration and acoustic dampers in structures.

3D printing saves both time and money here, because you do not need to manufacture a mold or order tooling for injection molding.(stratasys.com)

2. Silicone Molds and “Eggshell” Concepts

Another common use is the creation of silicone molds for casting resins or low-melting-point metals. In addition to traditional casting into manually prepared molds, an approach is also gaining ground in which you:

• print a thin-walled shell (eggshell),
• fill it with silicone or another material,
• and remove the shell after curing.

This method is already used today for the efficient production of silicone parts from 3D-printed molds and complements direct silicone printing synergistically.(cn.3dsystems.com)

3. Medical and Ergonomic Aids (for Prototypes)

Thanks to the biocompatibility of some silicone systems, it is possible to consider:

• ergonomic grips and attachments for tools,
• masks and sealing components for medical and protective equipment,
• prosthetic accessories and soft-robotic elements.

In practice, it is of course necessary to verify regulatory and material certification, but from a design and prototyping perspective, this is a highly attractive area.(stratasys.com)

4. Soft Robotics and Functional Prototypes

Silicone printing is ideal for pneumatic actuators, soft joints, membranes, and ible hinges. Combined with rigid plastics (printed using another XL tool), it is possible to create hybrid assemblies:

• a rigid frame made of PLA/PC/PA
• • and ible silicone elements for movement and damping.

A current trend in both research and industry is the combination of multiple materials in a single process – and the modular XL ecosystem with different toolheads fits well into this vision.(sciencedirect.com)

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Practical Tips for Getting Started with Silicone Printing on the Prusa XL

1. Material Selection

Not every two-component silicone is suitable for 3D printing. Look for systems that the manufacturer identifies as:

• suitable for dispensing heads / 3D printing,
• with a defined viscosity and pot life,
• curing at room temperature or with mild heating without the need for high pressures.

Materials with a very short pot life may cause etching and clogging of the mixing nozzle, while mixtures that are too thin may have problems holding their shape.

2. Printer and Environment Settings

Although the silicone head is plug-and-play, it is worth considering several points:

• Stable ambient temperature – a temperature that is too low may slow curing, while one that is too high may shorten the pot life.
• Clean print surface – although silicone adheres well to some surfaces, removable build plates or release layers should be used for repeatable printing (for example, a special film or a surface to which cured silicone adheres only weakly).
• Sufficient space around the printer – handling cartridges, mixing, and any cleaning require room.

3. Maintaining and Cleaning the Mixing Nozzle

Static mixing nozzles are consumables in two-component systems – after a certain period, the material cures inside them. The general procedure is:

1. After printing, extrude a small amount of material additionally to push out any bubbles and replace older material with fresh material.
2. If you know that printing will not resume for an extended period, it is advisable to replace the mixing nozzle.
3. Follow the recommendations of the toolhead and material manufacturers – some systems allow limited cleaning, while others are designed for more frequent replacement.

4. Designing Models for Silicone

Silicone behaves differently from rigid plastic. When designing:

• allow for greater ibility – parts deform significantly under load,
• for seals and O-rings, compression is crucial (typically 15–30% of the cross-section),
• consider supports – very thin overhangs may “run” or deform without support, even when the material is thick.

In many cases, it is advantageous to combine silicone with another material in the assembly – for example, design a groove or seat in a plastic part and print or insert silicone into it.

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How the Silicone Toolhead Fits into the Prusa XL Ecosystem

The Original Prusa XL is designed as a multi-toolhead platform – from standard extruders and high-temperature hotends to specialized modules. Adding the Filament2 silicone toolhead fits into the overall trend in 3D printing:

• from purely FDM plastics to multi-material systems,
• bringing desktop printers closer to industrial applications,
• and expanding the use of a single printer for multiple processes (prototyping, functional parts, tools, molds).

Industrial silicone printers using LAM technology or specialized IDEX machines still cost an order of magnitude more and target large companies.(innovatiq.com) The silicone toolhead for the XL represents a more accessible entry point into the world of real silicone printing for development departments, smaller manufacturers, designers, or university laboratories.

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Summary: A New Type of Project for Your Prusa XL

The new Filament2 silicone toolhead for the Original Prusa XL represents a significant expansion of the capabilities of desktop 3D printing:

• it enables plug-and-play printing of two-component, temperature-resistant silicone,
• bringing technology commonly found in expensive industrial systems to a standard large-format FDM platform,
• and opens the way to producing seals, dampers, molds, soft-robotic elements, and ergonomic parts, which were previously accessible only through casting or expensive outsourcing.

If you already use the Prusa XL for prototyping, fixture production, or small-batch manufacturing of plastic parts, the silicone toolhead may be precisely the step that turns your printer into a multi-material production workstation – without the need to acquire another specialized machine.

For a deeper understanding of the topic, it is worth following general trends in 3D printing of liquid and paste-like materials and thinking about projects not from the perspective of “what FDM plastic can do,” but rather what functional part you need – and which material (plastic, silicone, or a combination) is truly ideal for it.