Some Pencil Set for draft and loose idea. But also good for line drawing as well.
They can do sketchy drafts for early idea. 
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But Pencil 1 can do refine line art when scaling the pencil size down.
Example shown below:
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Pencil Blur isn’t exactly ideal for detailed coloring, but it could add some texture in the early stage.
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Enjoy, and happy drawing!
Pencil