A previous version of this blog post was published on October 25, 2003.
Finishing is where an HP Multi Jet Fusion (MJF) part becomes a production part. The right choice of finish depends on the material, how the part is used, and what it should look like in the field. This post covers the four MJF finishes that ABCorp 3D offers, which materials each one supports, and how to choose between them.
Why MJF finishing decisions matter in production
Production-scale additive manufacturing requires capacity et consistency. This applies as much to the finish as it does the print.
Post-processing finishes comprise a larger share of the total per-part cost than teams might expect. A survey in the 2019 Wohlers Report found that pre- and post-processing accounted for nearly 40% of the cost of an additive manufactured part (Additive Manufacturing Media). This underscores the importance of discussing finish options early in the design and production process so the cost can be budgeted accordingly.
Finish affects function as a sealed surface behaves differently in a wet environment than an as-printed one, for example. A smoothed surface is easier to clean, handle, and inspect, and a uniform color can hide slight printing variations.
The four MJF finishes ABCorp 3D offers
ABCorp 3D offers four industrial, automated finishes for MJF polymer parts including standard matte, dyed black, AMT vapor smoothed, and AMT vapor smoothed with black dye.
1. Standard matte MJF finish
This is the part as it comes off the HP Multi Jet Fusion line after depowdering and cleaning. It’s a matte grey color with a fine, even texture that is the fastest and most cost-effective finish because there are no additional steps.
Standard finish is the right call for internal components, jigs and fixtures, functional prototypes, and any part where cosmetics don’t matter. It’s also the only finish available for HP 3D High Reusability PP.
2. Dyed black
Dyeing gives MJF parts a consistent, uniform matte black finish without changing the surface texture. As-printed grey can vary slightly from build to build, and a deep black dye evens that out so parts match across an order and across reorders.
Dyeing is a staple finish for MJF parts, but manual dyeing can be messy and hard to repeat. ABCorp 3D dyes parts on a Girbau DY130 automated industrial dyeing system, which replaces that variability with a controlled, repeatable process. Dyed black works well for visible enclosures, housings, and assemblies where parts need to look the same.
3. AMT vapor smoothed
Vapor smoothing exposes parts to a controlled chemical vapor that melts and reflows the outer surface. Texture from the printing process flattens out and surface pores close. ABCorp 3D runs this process on an AMT PostPro3D system.
The result is a sealed surface that resists water absorption, is easier to clean, and resists bacterial buildup. That makes smoothing a strong fit for medical devices, fluid-handling parts, and anything handled often. Smoothing also brings out color, so full-color parts come out sharper and more vibrant.
4. AMT vapor smoothed with black dye
This finish combines both processes. Parts are dyed black and vapor smoothed for the most refined finish ABCorp 3D offers: a sealed, uniform, deep black surface with the same cleanability and moisture resistance as standard smoothing.
Choose it for customer-facing products, premium housings, and end-use parts where appearance and function both matter.
MJF finish and material compatibility
The availability of finish options depends on the underlying material, so we created this table as a starting point to help guide decision making. Our team of 3D printing experts can provide additional information based on your project requirements.
| Matériau | Best for | Standard matte | Dyed black | AMT smoothed | AMT smoothed + black |
|---|---|---|---|---|---|
| HP 3D HR PA 12 | Strong, functional, detailed parts at the lowest cost | Yes | Yes | Yes | Yes |
| HP 3D HR CB PA 12 (full color) | Full-color and color-coded parts | Yes | Yes | Yes | Yes |
| BASF Ultrasint TPU01 | Shock absorption, energy return, and flexibility | Yes | Yes | Yes | Yes |
| HP 3D HR PP | Chemical resistance, weldability, and low moisture absorption | Yes | No | No | No |
ABCorp 3D also prints in PA 11, PA 12 White, PA 12 ESD, and PA 12 FR. Finishing options for these materials depend on the application, so talk with our engineers before you specify. For material properties and powder reusability, see the ABCorp 3D materials guide.
Color options for full-color MJF parts
Dyeing isn’t the only way to add color. ABCorp 3D runs HP Jet Fusion 580 full-color printers, which build color into the part as it prints. There are three ways to use it:
- Single color: Assigns one color to the entire part before printing.
- Spot colors: CAD adds color to text, labels, and individual faces.
- Full color spectrum: Applies texture maps with tools similar to 3D animation software.
Printed color works well for color-coded assemblies, training aids, high-visibility parts, and patient-specific devices. Pair it with AMT vapor smoothing to seal the surface and sharpen the color.
How to choose an MJF finish for your application
Start with how the part will be used, then work back to the finish.
| Application | Recommended finish | Why it fits |
|---|---|---|
| Internal brackets, jigs, and fixtures | Standard matte | Lowest cost and fastest turnaround |
| UAS/UAV housings and visible airframe parts | Dyed black, or AMT smoothed + black | Matching appearance across lots, with a sealed option for exposed parts |
| Robotics enclosures and covers | Dyed black, or AMT smoothed + black | Consistent cosmetics and a cleanable surface |
| Medical devices, orthotics, and prosthetics | AMT smoothed, dyed or undyed | Sealed, cleanable surface |
| Fluid systems and reservoirs | AMT smoothed PA 12, or standard PP | Resists water absorption |
| Customer-facing products | AMT smoothed + black, or full color + smoothing | Most refined look and feel |
A few questions narrow the choice quickly. Will the part be seen? Will it be exposed to liquids or cleaning agents? Does color need to match across reorders? What are the per-part budget and lead time?
Design considerations for finished MJF parts
The best finishes start in CAD. Vapor and dye need to reach every surface, so enclosed volumes need vent or drain paths. Consistent wall thickness produces more uniform color and smoothing. Vapor smoothing reflows a thin layer of the surface, so flag tight-tolerance features before you quote.
Our engineers review these details during design consultation, before they turn into rework.
Consistent MJF finishing at production scale
Finishing only adds value if it’s repeatable. ABCorp 3D runs dyeing and vapor smoothing on automated industrial systems inside a secure, U.S.-based facility in Boston, home to the largest HP Multi Jet Fusion operation on the East Coast.
Automated inspection with a SolutionIX C500 scanner supports first article inspection, with accuracy down to 0.01 mm. That lets our team verify finished parts against the model, not just printed ones. It’s all backed by quality systems certified to ISO 9001 and ISO 13485.
Discuss your finishing requirements with ABCorp 3D
The right finish depends on the part, its material, and how it will be used. Our team of 3D printing experts consult with customers to choose a finish that supports their project without slowing it down. Contact us to learn more.
