TIPS WITH TONY: Mixing It Up with Plastic Colorants

Proto Labs’ material selection and available color options for thermoplastics can be found online at

You may require colored resin or transparent coloring for your injection-molded parts, but exactly how much colorant is added and what consistency can you achieve?

Salt-and-Pepper Mix
Proto Labs offers colorant at no charge to most natural, white or clear materials. In most cases, we do this by adding a 3 percent salt-and-pepper mixture of colorant based on weight to the base resin, but on occasion, less colorant is added to transparent resins like polycarbonate.

A 3 percent salt-and-pepper colorant mix is typically used.


Since we hand mix the colorant and base resin, you may have a higher or lower concentrate of colorant throughout the order. The injection molding press does a good job of mixing the colorant and base resin when it melts and grinds the resin in the barrel before molding, but it isn’t 100 percent.

Pre-compounded Resins
Note that when ordering a colored or transparent part that requires specific color-matching or a color consistency that may be difficult to achieve with a hand-mixed colorant, we recommend using a pre-compounded resin from a plastics supplier such as or

Pre-compounded resins allows the color to be fused into the actual base resin. And in order to achieve a certain consistency or match a specific Pantone, a plastics supplier is your best option.

Colorant pre-compounded with base resin provides Pantone matching and consistent coloring.

Coloring plastic can be done easily and the majority of customers who need colored plastic, use a hand mixture of 3 percent colorant as this works well. If you have any questions on colorants, please contact one of our customer service engineers at or 877.479.3680. Proto Labs also has additional design tip resources that discuss additives and colorants along with an informative video.

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About Tony Holtz

Tony is a technical specialist at Proto Labs with more than 10 years of experience ranging from CNC mill operator to mold designer to customer service engineer. While his formal education is in industrial machinery operations, he has extensive knowledge and experience in both traditional and advanced manufacturing processes and materials. Throughout his tenure at Proto Labs, Tony has worked with countless designers, engineers and product developers to improve the manufacturability of their parts.

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