3D printing in color has been around longer than you think. Do you need a prototype printed in yellow ABS? No problem, load a yellow spool of filament in your 3D printer and voilà! You have yourself a yellow part. How about blue? We have you covered, just toss some blue photopolymer in your SLA vat and BAM! A blue part can be printed. How about a part with multiple colors? No problem. Break out the trusty sandpaper and good old-fashion elbow grease, maybe some primer, then either spray or hand paint your model until your heart is content.
Oh… you were hoping to have full color printed parts straight off the printer? Why didn’t you say so? Let me introduce you to Stratasys PolyJet technology.
Stratasys PolyJet technology is a 3D printing process that sprays special liquid resins called photopolymers that turn from a liquid to a solid when exposed to UV light. With a traditional 2D color inkjet printer, there is a series of printheads that move back and forth printing a color image on a piece of paper with typically 4 colored inks (cyan, yellow, magenta and black). Now imagine replacing the paper on that printer with a build-plate, and the ink with photopolymer.
By replacing the paper with a build-plate that slowly lowers itself down into the machine, we can repeatedly print an image many times on top of itself making it thicker and thicker with each pass. Because the ink in this example is now a photopolymer, we can flash a UV lamp on the photopolymer between passes of the printhead to turn the just jetted liquid polymer into a solid rigid layer of material.
By using multiple printheads and resins (inks) just like the 2D color printer, the PolyJet printer can jet multiple colors of photopolymer simultaneously to print full-color parts that are basically stacks of thousands of 2D images printed one on top of another.
3-Color Blend Color
The Stratasys Connex3 line of printers can print with three different resins or one at a time. In the world of color, this means it's possible to load cyan, magenta and yellow resins into the machine and get a wide range of colors enabling the printing of full-color parts with no need for additional painting. There are some limitations on colors that can be achieved in tints and shades because neither black nor white is in the mix when doing full color. To hone in on one particular range of colors, a Connex3 printer can be loaded with two colors plus a white, black, or even transparent to get more tones out of secondary colors.
6-Color Blend Color and Beyond
While the Connex3 is capable of an amazing array of colors that is far beyond other previous technology – Stratasys always had bigger plans for what could be done by adding black, white and even clear to a three-color mix. The J750 and J735, which were the first machines from Stratasys to utilize 6 different model resins at one time, opened a totally new world of 3D printed color.
By jetting cyan, magenta, yellow, black, white and clear resins simultaneously, the J-series printers can create a range of over 500,000 color combinations. This capability opens the doors for a wide range of markets including education, consumer goods, automotive and medical industries to produce models and prototypes with detail and finishes that were previously unattainable with little to no post-processing needed.
Vivid Color Printing
With vivid resins that boast very vibrant pigment loads, Stratasys PolyJet technology maintains better saturation when mixed with other colors than their predecessors did.
The Stratasys J-series, Connex and larger Objet printers have the capabilities to provide excellent detail in a wide range of brilliant colors and have opened entirely new industries of adoption in areas like automotive lighting, electronics and consumer packaging prototyping.
Opaque Color Printing
Opaque colors provide strong contrast and beautiful color separation while offering exceptionally high-quality, full-color models with realistic finishes. The VeroUltra™ family of colors meets 2D graphics standards and you can create super-realistic models using labels, graphics or text to simulate silkscreen printing or printed stickers. Use VeroUltra White and VeroUltra Black together with PolyJet Vivid colors for highly professional full-color models, with realistic finishes. The possibilities are endless and the ability to create a prototype with a realistic final fit, form and appearance in a single print dramatically reduces production time.
The PANTONE Matching System (PMS) is the leading global standard for color matching. There are specific requirements within PMS that must be met in order to become PANTONE-validated. Stratasys meets all of these PMS requirements with the technology in their J-series printers allowing them to be the only 3D printers that are PANTONE validated.
In 2019, the Stratasys J735/J750 and J835/J850 PolyJet machines successfully passed the rigorous requirements needed to make them the world’s first and only PANTONE-validated 3D printers. This is important because the PANTONE language is a universal color code that is not limited by CMYK or RGB color combinations and bridges the gap for designers and manufacturers. It assigns each color with a code to ensure you are talking about the same shade. Add the J55 into the mix, and you have a wide range of options that can create everything from quick design iterations to high-quality final prototypes in a compact, affordable and office-friendly way.
Voxel printing allows users to actually program the product material and its viscosity on a microscopic level. This results in both incredible control over color for visually stunning results and opportunities using a spectacular range of material properties allowing for new and exciting composite materials.
Voxels are similar to pixels but in a 3D space. The word "voxel" actually comes from the term "volumetric pixel". Much in the same way pixels can be combined to make colors and patterns, voxels can be combined to do the same. This is important because Voxel technology gives users the capability to go beyond the previously limiting two-dimensional space to a scope that includes the ability to duplicate originals identically and print parts with high resolution, realism and consistency.
But Wait, There’s More!
Thus far, we have only talked about the mixing of colors. Stratasys PolyJet 3D printers can also print resins with various hardness and flexibilities which can be mixed together to create blended materials with unique physical properties called Digital Materials. Some examples include:
PolyJet in Film
Laika Film Studios leveraged PolyJet technology to change the way movies are made. The Laika rapid prototyping department changed the facial characteristics of the puppets for many of their recent films by utilizing multi-material 3D printed facial parts that were printed using Voxel Print technology. This resulted in higher resolution parts with realism and consistency.
PolyJet in Medicine
Patient-specific anatomy replicas are being made using The J750 Digital Anatomy Printer (DAP). These models have the same feel as real human bone and tissue. Being able to control the softness and rigidness on the smallest level possible allows the parts to achieve their feel of real anatomy. These structures are auto-generated, so all a doctor has to do is take in their segmented anatomy, import into GrabCAD Print and assign the desired anatomy to the areas they would like.
A 3D printed liver model makes teaching students about blood flow easier.
PolyJet in Fashion
PolyJet materials even have a place in the fashion industry. The Chro-Morpho Collection has transformed the fashion industry with unique 3D printed designs. Stratasys, along with threeASFOUR's Travis Fitch and Julia Koerner, set out to innovate a one-of-a-kind approach to 3D print items that would appear to be a different color from various angles. They also incorporated the idea of light-filtering butterfly wings into the design and printed it directly onto fabric. Each garment has thousands of microscopic polymers that bounce light when being looked at from different angles creating a color shift.
As you can see, the options are virtually limitless and Stratasys is the gateway to the world of multi-material color 3D printing. Create brilliantly colored prototypes to fit your application needs, whether that's translucent, rigid or thermal-resistant.
With the widest range of material properties and colors available, you can feel empowered to print any type of multi-color, multi-material models you may need: from rigid to flexible, transparent to opaque, neutral to vibrant, standard to bio-compatible and durable to high temperature.
Want to know how to improve your design process with PolyJet materials? Download our guide, Design Cycle Efficiency With Multi-Material 3D Printing.