This is 4 brushes that I am calling stents because that kinda fits what they look like. They have a bit of dimension to them because they don't fill the space completely so you can see it crossing its own path
The doodle zones at the bottom of the examples are just little scribble doodles using the pens tested on that page so you can see them in action a bit more.
I'm calling them stents because they look a bit like those metal mesh tubes and I can't think of the word for when those are used for protecting electrical wire, so we are going with the word that I presently have (because these are the words I presently have)
Brushes