Above is a tutorial by Ocean Quigley on how to make a non-photorealistic shader for Blender that looks like an etching or engraving. I was lucky to work indirectly with Ocean on SimCity 4, and he remains one of the most intelligent people I’ve ever met.
Here, he makes the baffling process of shader creation seem not simple, but at least attainable. I definitely can’t claim to understand every step of the process he outlines, but he does do a great job of walking through step by step and explaining why he’s doing each part.
A simpler but interesting effect is explained by Ian Pitkanen, with this video demonstrating how to add a grainy effect to lighting transitions. It’s a nice, subtle effect that makes 3D objects seem less sterile and more like they’ve been printed on paper.
I’m frequently trying to learn how shaders work (and then getting hopelessly confused and giving up). One of the most useful-seeming resources is The Book of Shaders by Patricio Gonzalez Vivo and Jen Lowe, which encourages you to interact with the examples instead of just passively reading. This is a perfect approach, because it’s a reminder that this isn’t magic, but neither does it require a deep understanding of math. It is presumably possible to understand the basics and then experiment until you get what you want.
The reason I’m interested in shaders at the moment is to see if I can use Blender to make art resources for a possible game for an upcoming black-and-white video game device. This article by Braden Eliason on getting that classic Mac dither effect in Blender seems like it’ll be invaluable for that!