Simple Sketch Pro is a Blender add-on that simplifies creating line art illustrations and animation. It comes from Chipp Walters and the team behind KIT OPS, which has over 100,000 customers. The add-on suits technical illustrators, cartoon or graphic novel artists, and people producing industrial and architectural design sketches.
Its interface gives one-button access to six professionally designed presets: Black and White, Ambient Occlusion: Clay, Blueprint, Sketch Style, Transparent, and Comic. You can apply a preset or work from your existing scene, and switch between the two. Line weights and colors are adjustable, and a Screen Space option keeps lines at even thickness no matter the perspective.
You can also override material and line art settings for any object in the scene. Documentation is included, and a demo video is available.