Look close at the detailed vacu-form band. There are some of the raised areas painted black.
The 3D parts included two of the wraps. One was joined to slide over the larger tube. The other was flat, meant to be rolled around and glued to the tube.
I didn't use the flat one on the model. I used it to practice the black markings like in the catalog picture.
Using the side (not the tip) of a Sharpie, the highest points of the print got some black details.
This gives an idea of how much black was used.
Just enough -
