Thanks for sharing! Today I discovered the Jibun Techo. Always great to discover products made by people who put so much thought and craft in. Not surprising the Japanese excel in this art.
Set the mood for today.
Unfortunately can't upvote.. your karma says 6666. May return when the spell is broken.
If you're inking your drawings, you probably don't need to worry all that much about the exact line width and consistency of your pencil work.
N.b. I don't ink my drawings. I've used drafting pens a couple times to experiment, but it's not part of my regular workflow.
https://www.jetpens.com/blog/The-Best-Technical-Drawing-Pens