Mosaic Palette 2 Frist Look

First successful print with Palette 2

The Palette 2 is an appealing device for multi-material printing if it works like Mosaic says it should which is splicing filament changes and queueing up those splices to match layers and sections of layers that use different materials.

For this first look my setup consists of a Palette 2 (not pro), Canvas Hub, and I used Canvas exclusively for slicing. All of this was connected to a Prusa MK2S.


Setting up the hardware is fairly simple. Nothing to build. You will be picking the right PTFE tube length for your printer and either using the included velcro PTFE tube adapter or you will need to print out an adapter for some printers. If you get the Canvas Hub you will hook up USB connections to the Palette 2 and your printer.

If you are using the Canvas hub or are using Canvas to slice models you will need an account at If you have a Raspberry Pi with Octopi you do not need to buy a Canvas hub because Mosaic just adds their own plugins to the existing Octopi software. If you do not have either the Canvas Hub or a Raspberry Pi with Octopi you can still slice and download files to print with the Palette 2 and your 3D printer. My understanding is Palette 2 works better with Octopi because there is communication between the printer and the Palette 2 handled by Mosaic’s Octopi plugins. At this time I’m not sure exactly what that communication involves.

Canvas Hub


I highly recommend watching the setup videos online for Palette 2 and Canvas Hub. I would also check Mosaic’s website for updated information before relying on the included setup guide. Mosaic also has information on using Canvas (the web based slicing tool) which you should watch as well.

Once you’ve plugged in your Palette 2 and send your first print the Palette 2 should go through first-time printer setup. My Palette 2 did not seem to respond when the first print was sent and after some basic troubleshooting and disconnecting and reconnecting the Canvas Hub connection in software to the Palette 2 it finally started the first-time setup.

This was a fairly easy to follow process that involved:

  • Inserting the correct color filament into the Palette
  • Wait for it to create filament by splicing the filament together within the Palette 2 device
  • Feed clear filament into your printer (or really just a different filament color than what your Palette 2 will be sending)
  • Teaching the Palette 2 how much filament it takes to get the new color out of your nozzle by slowly feeding the Palette 2 output filament through your extruder until it appears out of your nozzle
  • Starting your first print


Once the print starts you will see your 3D printer output filament based on your model and in between each filament splice it will print to a purge block to ensure you are printing fully with the correct color.

Purge block changing from Black to Silver

This, of course, means printing significantly more filament than you would for a single material print. This also means drastically long print times in some cases.

My first print was not the Mosaic keychain test print. I should have started with that, but I wanted something more interesting. The result was starting a 6 hour print that showed some errors either with slicing or calculating the amount of filament needed. 

Squirtle with stripes where there shouldn’t be stripes

I stopped the print and tried another model. The two-color casino chip was far less ambitious and came out quite well.

Two color casino chip and purge block

With a success I then tried again to print a more complicated model (two color Flexi Rex). The print started great with the two colors switching for the first few layers.

Unfortunately the silver and the brown slowly swapped resulting in the incorrect color and I canceled the print.

I reluctantly downloaded the Mosaic logo keychain to print. On the surface it looks like it could be a very long print, but it was clearly designed to print fast which I appreciate. The keychain printed the colors correctly with some slight issues with either under extrusion or slicing.

Mosaic keychain logo

You can see some of the brown in the green and purple but that is because the filaments I used were clear and the way this prints fast is by only changing colors on the top few layers. Despite the under extrusion or slicing issue I rated this a 4 as recommended by the Mosaic forums. The rating system helps the Palette 2 determine good prints from bad and in this case it was good in terms of getting the color down correctly.

Issues and Observations

I have been using 1.0.1 firmware and so I expect some of these issues will be fixed in time. The Palette 2 never missed a splice over the few things I printed. The touch screen interface responds quickly and is easy to use.

While using the Palette 2 with Canvas hub I found that after a failed or successful print I had to disconnect and reconnect the Palette 2 every time within the Octopi plugin or the Palette 2 would never respond to a command to start a new print.

At some point the Canvas Hub with Octopi stopped being able to connect to the Canvas cloud. I could never get it to reconnect so I ended up downloading the files from Canvas and uploading them onto the Canvas Hub which kind of defeats the purpose of the connected ecosystem.

At the time I was testing there were limited printer profiles in Canvas. You can upload your own, but you at least have to have a little knowledge of GCode to check and make sure what Canvas is using for your printer is acceptable. I hope they can work on adding more printers to their official supported list.

In my experience the Palette 2 never missed loading and unloading filament from the four inputs. The Palette 2 also was able to predict how much filament needed to be extruded before the start of second and later prints based on previous prints which is quite clever.

The  Palette 2 hardware looks to be well designed. I love that you can open up the case and see exactly what is happening on the inside. There are a lot of moving parts, and while I did not have any issues with splicing or loading/unloading, I suspect something like this is more susceptible to issues down the road. This isn’t a knock on their design, but more that something like the Palette 2 is more complicated than just a standard extruder.

In terms of noise the Palette 2 fan is louder than a MK3 but quieter than a MK2S. The device makes  a lot small noises as the filament is moved through the hardware, but the loudest noise is when it cuts the filament. That said, it isn’t terribly annoying.

Conclusion and Final Thoughts

Overall I am excited to see what I can do with the Palette 2. A 50% success rate isn’t a great start, but I am the first to admit I did attempt more complex models to begin with. I think printing a number of easy prints, like the Mosaic keychain, and rating them makes sense before moving on to more complicated models. I encourage new owners to follow this path.

Once the PLA multicolor prints working reliably I intend to try soluble supports and different materials including PET and flexible filaments. Multiple colors is nice, but ultimately that is just the start of what you should be able to do with a multi-material device for your printer.

I am hoping Mosaic continues to refine their firmware and the Canvas system. I imagine all the issues I’ve run into are things that can be addressed in software or slicing.

Please see my about page for information about reviews on this site.

Commissioning 3D prints from hobby printers

You might not own a 3D printer, but you may want or need something printed. There are a number of commercial printing services that allow you to upload a model and have them print it in a number of different materials. Despite either having or sourcing massive printer farms these services are often the most expensive option for your one-off print.

Print farms are designed to print a large number of models usually at a single quality. Anything custom is going to cost more like changing layer height, infill, material, or print speed.

You might want to consider finding a hobby or semi-professional printer instead of a print farm. Before you do that you should know the limitations of FDM/FFF printers. These are printers that lay each plastic layer one at a time building up from the bed of the printer.

Some models are simply not printable

This is especially true for 3D models that were not designed for 3D printing to begin with. Some models can visually look fine but have thousands of errors for a 3D printer. The best models are solid or water tight (but does not have to hold water). This means there are no gaps between inner and outer walls of the model. It also means there are no 3D elements of the model that either are separated by an air gap, or improperly merged so the model contains crossed over geometry.

Extremely small models could lose detail or simply fail to print. Very large models may not fit on the printer without cutting it into multiple pieces.

Very complex models may result in repeatedly failed prints or just be too complex for software to figure out how to print it in layers.

You cannot print clear on FDM/FFF

There are clear or semi translucent filaments available, but a printer will never be able to print glass clear. The nature of melting plastic layers together reduces transparency. There are some post print techniques that can get more transparency but it will never be clear.

Some materials cannot be used outside

PLA will eventually breakdown or crack in direct sunlight. This is the most common, easiest to print, and one of the cheapest print materials so a lot of people use it as their go-to material. Other plastics may hold up better but almost all of them will fade, change color, or completely lose their color.

Printed parts should never be used when safety is needed

This means you should never use a 3D printed plastic part where someone’s health and safety is reliant on that part not failing. Some obvious examples would be rock climbing gear or functional car parts.

This extends to food safety as well. Because printers put each layer down prints have many microscopic holes that bacteria could get into. It is almost impossible to clean these parts fully. You might, however, be able to apply a post print coating that could make printed parts food safe.

Some materials and colors show layer lines more than others

Typically white or shiny colors will show printed layer lines giving you the impression that the print is worse than the same model printed in another color. Semi translucent materials hide pint layers well, and some colors just naturally hide these lines better. Some of this can be mitigated with smaller print layers (significantly adding more time to the print), but the reality is, even on the absolute best print, you will see print lines if you look close enough. Post sanding and finish work can all but eliminate these layer lines.

Most hobby printers do not have multi-color capability

And even if they do expect these prints to cost significantly more due to increased print time, more prone to failure, and increased material for color changes. Most 3D models you find online will not be multi-color ready.


  • Find a local printer. This means faster turn around and minimal or no shipping costs. It also allows you to establish a relationship with someone local if you find yourself needing another print in the future.
  • Ask for well lit high resolution pictures of the printer’s other prints. If possible, be specific and ask for images of the same material, color, and print settings. This gives you a better idea of what to expect.
  • Some prints (like figurines) will require a huge amount of support material. Detailed models will need significant clean up time which can add to the cost.
  • You should expect your hobby printer to give you an accurate quote. All print software can estimate time and material use.
  • Be understanding of delays. 3D printing is not at the paper printer point. They are more likely to run into problems than most other appliances. Failed prints can be the printer owner’s fault, but a lot of the time it can also be poorly manufactured materials, errors from the software creating the print, and other issues outside of a printer’s control.
  • Do not accept clearly awful prints. Use the example pictures, suggested above, as a benchmark.
  • If you want a model modified expect to pay a lot more. 3D modeling is not easy and takes a lot of time to learn. Not all hobby printers can make changes, but those that can will charge a high rate by the hour (expect between $40 and $150 an hour).
  • If you want a model designed from the ground up to your specifications expect not only to pay for that modeling time noted above, but also expect to go through at least 3 iterations before you get a final model. Even more iterations may be needed for a functional part. You should expect to pay for every iteration. No one will be able to design and print the prefect model the first time.
  • Consider offering a barter for 3D prints. Some people are good at modeling and printing but might lack the painting and finishing skills. This is a great opportunity to help a fellow maker and limit both your costs.

3D Printer Safety

If you own or are considering purchasing a 3D printer you should be aware of the potential hazards involved. Please research your printer or the printers you are considering to find out if it has a higher potential for fire and  if there are ways the community has made the printer safer.

Buy a Printer with Safety Features

Your printer should have firmware (software that runs the printer) which has:

  • Hotend and bed thermal runaway check.
  • Minimum temperature check
  • Maximum temperature check

Thermal Runaway: printer is cooling down faster than it should be or not heating fast enough. This check ensures the thermistor (the device that measures temperature), and the hotend (the part that melts the plastic) are performing as expected. If the hotend is being asked to heat to 215 °C but the thermistor is reporting that the temperature is actually going down, there clearly is a problem. Some printers will simply try to heat the hotend more to compensate and this can actually result in a fire.

Max and Min Temp: If the slicer software requests a temperature of 900 °C it will ignore the command. If the printer detects a temperature below expected cold room temperature or something radical like -600 °C – a sign the thermistor is not working. In both cases the printer should stop printing and turn off power to the heat bed and hot end.

Additional Safety Features:

  • Fans spin up to full blast to help prevent the hotend from overheating in the event that the thermistor is incorrectly reporting the temperature or some other temperature related failure has resulted in the hotend attempting to heat up beyond its usable temperature.
  • Printer that detects fans are not working.

Some cheaper printers come with bad wiring, uses wires that are rated for lower than the amperage being sent over them, or has not fully secured wires either in the power supply or on the circuit board running the printer. Check reviews to see if the printer you have or are interested in suffers from this and usually the community will have a solution available.

If you are building the printer from a kit make sure you follow the instructions carefully. This is most important when it comes to wiring the power supply and heat bed. A loose cable can result in a short which can cause a fire if a printer is unable to detect thermal runaway.

Do your research and make sure you are getting a printer that has safety checks enabled and are proven to work.

Fire Alarm

Please buy a fire alarm and put it directly over your printers. The faster you are notified of a catastrophic problem the better chance you have of getting to safety or even saving your property.

Don’t Rely on Fire Suppression Alone

Some people have suggested using a fire suppression system like those found in kitchens. The idea is if a cooking fire gets out of hand the heat will melt a switch that dumps fire suppression powder or foam. This is usually ok for cooking fires because the source of the fire is extinguished (food) and, even with the burner continuing to heat, typically the worst that happens is smoke damage.

I don’t believe this is as useful with 3D Printers because the problem isn’t that the hotend (burner from the example above) is on, but that the hotend is heating well past safe levels due to a printer malfunction. While the initial fire might be suppressed, another one can easily start from molten aluminum reaching other flammable parts on the printer.

Another option is to run your printer in a fireproof or resistant enclosure (steel or concrete). If it is fully enclosed flames would be better contained in the event of a fire.

You should check with your local fire department for expert advice in regards to handling fire like this with a fire suppression system.

Unsupervised 3D Printers in Multi-Unit Homes or Public Buildings

If you are operating your printer in a location where other people’s lives may be at immediate risk in the event of your printer malfunctioning like at a school or apartment building, you should seriously consider never running it unattended.

At a minimum, you should thoroughly test a printer you don’t have experience with to ensure it is reliable and then regularly test to make sure sensors and safety features are working as expected.

Children and Printers

Make sure children are supervised when using a 3D printer. For those of you with small children you should be aware that the hotend on a 3D printer, which melts the plastic, can get up to 300 °C which is 570 °F. This is typically hotter than your electric oven can heat up. The printer bed, if heated, can get up to 90 °C which is 194 °F. Both these temperatures are capable of causing serious burns.

Many printers, especially cheaper ones, do not come with an enclosure. This is to save costs or, in the case of printers primarily used for PLA, to avoid an enclosure heating up too much and negatively affecting print quality. The printers that do have enclosures do not usually have a lock or child safety mechanism.

Particulates and Fumes and Toxic Materials when Printing

This topic isn’t discussed much, but be aware your printer generates invisible, but often smelly, particulates while printing. Some materials are worse than others (ABS compared to PLA). There is not significant research to show printer fumes and particulates are bad for your health, but you might consider using the printer in a room with decent ventilation.

A lot of what has been discussed covers FDM or FFF printers which melt plastic and put it down in layers. Another type of 3D printer that is becoming more popular are SLA printers that use UV cured resin which is toxic before it is cured. You should not touch liquid resin until it has been washed in alcohol and cured in UV light.

Don’t Take My Word For It

Hackaday –  3D Printer Halts and Catches Fire

Hackaday – Don’t Leave 3D Printers Unattended

Thingiverse – Anet A8 almost burned down my house

Punished Props – Avoid a Fire Hazard

Maker’s Muse looks at safety when it comes to SLS printers that use resin:

Maker’s Muse – Resin 3D Printing Safety – Important for Beginners!

Thomas Sanladerer – Everything you need to know to make your 3d printer fireproof!

Thomas Sanladerer – Testing my printers for fire hazards – results all over the place…

More advanced users can modify the firmware on their printers using Marlin to enable safety features:

Thomas Sanladerer – Maker your 3D printer safer: Marlin configuration!

Damaged thermistor reports the wrong temperature and hotend continues to heat until fire in this test. Example of what can happen if your printer does not have thermal runaway protection:

Chris Bate – Hotend thermal runaway test #2