June 12, 2019

Using Finishing Options for Injection-Molded Parts

By Protolabs

When designing injection-molded parts, you may need to apply finishing options after your parts are manufactured to improve mechanical properties, enhance surface finish, facilitate the assembly process, or further customize parts. Another benefit? You can streamline your supply chain and injection molding needs—prototyping, production, finishing—through a single, digital manufacturing parts supplier.


Mold Texturing. Mold texturing involves applying industry-standard Mold-Tech finishes to a mold. With mold texturing, designers can highly customize their finish. Lead time for mold texturing at Protolabs typically adds nine business days to your mold order.

Part Marking

Pad Printing. Pad printing transfers a two-dimensional image, such as a company logo, onto a three-dimensional object. For example, medical device company HemoSonics recently used pad printing (pictured below) to place company logos on its blood analysis machines. All images are reviewed for size, color, and complexity restrictions, and images for printing should be provided with locations clearly marked in reference to part geometry. PM-TI and MT11010 are the most aggressive textures we can pad print. Required lead time for pad printing at Protolabs typically adds three-plus business days to your parts order. 


Laser Engraving. Laser engraving, which is applied to the mold or directly onto the parts, is frequently used for information such as logos, serialization, or part numbers. Laser engraving ensures crisp, consistent information on each part. Acetals, and high temperature materials are not suitable for laser engraving. Lead time typically adds four-plus business days to your parts order and, nine-plus business days to your mold order.

Threaded Inserts/Tapped Holes

Finishing Options: Required Inputs

Mold Texturing:

  • CAD/part link
  • 2D drawing/image with faces to be textured
  • Desired texture (e.g., MT 11010)

Pad Printing:

  • CAD/part link
  • 2D drawing noting location of graphics
  • Adobe Illustrator file noting size of graphic
  • Part quantity
  • Material: Only ABS, PC, ABS/PC are available
  • Color specification (Pantone #)

Laser Engraving:

  • Drawing or CAD identifying size
  • Location and depth of engraving
  • Part quantity, if applicable
  • Material

Threaded Inserts (Heat Staking, Ultrasonic Welding):

  • CAD/part link
  • 2D drawing noting insert type and location
  • Assembly CAD, if possible
  • Part material, quantity

Basic Assembly:

  • CAD/part link
  • Assembly drawing or CAD
  • Part quantity

Heat staking and ultrasonic welding are the two methods we use at Protolabs to produce threaded inserts if insert molding is not an option for your design. Heat staking is the process of heating threaded inserts and press fitting those inserts into part geometries. At Protolabs, this option is only available for threaded inserts as we are not able to accept custom inserts at this time. Ultrasonic welding uses high frequency acoustic vibrations to press fit inserts into part geometries. Like heat staking, ultrasonic welding is currently open to threaded inserts at Protolabs, and custom inserts are not accepted. Lead time for both of these processes adds five-plus business days to your parts order.


Basic Assembly. Our basic part assembly options include fastening parts together that have been manufactured by Protolabs and/or applying labels to individually bagged parts. We are not able to accept customer-supplied parts for assembly at this time. Lead time is typically three-plus business days to your parts order.

Kitting/Packaging/Labeling. This service involves creating a parts kit, specialized packaging, and/or labeling, which can be used as an input to fulfill manufacturing jobs or sent to a customer as a completed product. Lead time is typically three-plus business days to your parts order.

For additional help, feel free to contact us at 877-479-3680 or [email protected]. To get your next design project started today, simply upload a 3D CAD model for an interactive quote within hours.