For those who use 3D printing to prototype or productize designs on a recurring basis, you may have noticed that some filament producers do color materials better than others. Truth be told, it’s extremely difficult for these companies to obtain the exact same color for every fresh batch of filament. Not only do minuscule and sometimes uncontrollable nuances affect the production process, these producers must constantly strive to match Pantone or RAL color references (those colored swatches you browse through will choosing a paint) in order to match consistency.

Filament color vs reference

In order to gain better insight on how filament manufacturers keep their colors consistent, we talked to Alexander Pelayo from Taiwan-based company Voltivo, one of the premier filament producers in the world, as well as Florian Deurer, the lab manager from the equally prestigious German filament manufacturer 3dk.berlin.

For starters, it’s important to know that when both PLA and ABS are in their rawest material state, they are completely colorless. So, when it comes down to adding color to the filament, it’s all about keeping the process as consistent as possible. “You need consistency in every aspect,” says Pelayo. “If you have ABS or PLA, it comes out colorless, in what we call a natural beige. It’s what the raw materials are without color additives, which comes when we add pigmentation. The trick is that every aspect of the production stays unchanged, from the raw material, to the temperature it’s being produced at and extruded. All of these aspects influence the final product and the color.”

There are many factors that go into the both the filament production and coloring process. For both 3dk.berlin and Voltivo, the focus is on perfecting the production process and then keeping the consistency going. As Pelayo said during our recent conversation, “you can’t cut any corners”, and that’s what sets cheap filaments from premium ones. 3dk.berlin’s Florian Deurer broke down the many factors that go into maintaining color consistency. “The secret to produce a consistently colored filament is to have a sufficient intermixing of the material inside the extruder,” he said. “It depends on the speeds you run the machine, the preparation of the materials, temperatures, and, last but not least, on the design of the extruder, the quality of the screw, and the sheer size of the cylinder and screw.”

Now, whether you are using your 3D printer for prototyping, artwork, or for product design, chances are you might be dependent on the having the exact same color of filament, this consistency is supremely important for many. But, changes in color tones aren’t the only mishap that can come from screwing up the pigmentation process, poor filament production can also lead to problems with your printer, which is we all know, is something we prefer to avoid. “If you get it wrong, the color changes over the meters of filament, or even worse, you get agglomerates of pigment which form into blob and, if not detected, will eventually clog the 3D printer’s nozzle. Therefore, we measure the filament diameter constantly with an laser array and have an automatic blob alert, so if there is any failure, it cannot get onto the spools”, Drurer said.

One example that Pelayo shared with me to prove the importance of color consistency was about an ambitiously large project where Mamou-Mani, a renowned architect, needed an abundance of of a specific shade of white filament to create Food Ink, a 3D printed restaurant located in the heart of London. He decided to turn to Voltivo, who had to ensure that the mass amount of filament they provided Mamou-Mani was the exact same shade of white. “If he used different spools, then the table would be a different shade of white then the stool you sit on. No, it needs to be uniformly white.”

So, at the end of the day, the filaments that have a higher price tag usually contain more consistency in color, as well as higher print quality too. In Voltivo’s case, they have committed to putting the Pantone reference on every one of their filaments, ensuring that customers know the exact color that will end up being extruded from their 3D printers. For quality color, producers must focus on consistent protocol and effort. If you were to compare a cheap colored filament next to one produced by Voltivo or 3dk.berlin, you would almost certainly notice that the difference both before and after printing.

Is the color consistent after printing ?

As Pelayo reiterated throughout our conversation, it’s all about putting in effort and not cutting corners, especially when it comes to saturating the filament in pigment.

“Another thing as well is that we go through very deep saturation. If you take some really cheap filament and break it up, often it’s milky white inside, and that’s what happens when you don’t use enough pigments, Pelayo said. “Obviously, the cheaper the filament is, the more corners are being cut, and good pigments are not cheap. We commit to the Pantone color and having the same color every time, so we make sure to use the same pigments with our filaments.”