I use a Sanford ProTouch II 0.3 mm mechanical pencil, which was later sold under the Papermate brand. They were made in Japan. Unfortunately, they have been out of production for many years. I bought them a long time ago. They are at least 25 years old. If you are able to find a used one anywhere, it will be very expensive. These pencils are unlike any other. With a perfect weight and balance, they are a joy to hold and use. I do not know why they stopped making them, as they are some of the best pencils ever produced.
The Sanford ProTouch II has a high quality, thick brass clutch, much beefier than the GraphGear mechanism. The eraser is a white plastic (vinyl?) material, like the "Staedtler Mars" eraser. The eraser extends and retracts when you rotate the top. The knurled grip feels good in the hand, and the little ring can be rotated so the window shows the type of lead in the pencil: H, 2H, 3H, 4H, B, HB, and F.
I have always used ultra-fine-point mechanical pencils for my work, ever since I discovered them in college. I like the fine lines that they produce. Despite all the training (and teaching others) to write notebooks with an ink pen, I never did. Fortunately, I was never called to testify about my notes in court.
These days, I use 0.7 mm mechanical pencils in the shop. I would prefer to use 0.3 mm or 0.5 mm, but they are too delicate to draw on wood. Wood grain snaps the leads too frequently. I keep a 0.5 mm Pentel P205 in the shop, but rarely use it. For the finest lines on wood, I use marking knives and gauges, sometimes shaded with pencil so I can see them.
Another reason I like 0.7 mm pencils in the shop is that I can make them myself. My current favorite is a pen and pencil set made from zebrawood. I keep the pencil in my shop apron and use it for drawing on wood and writing notes in a woodworking notebook.
Many different 0.7 mm mechanical pencil kits are available for making your own pencils on a woodturning lathe. The pencil kit mechanisms are okay, but not great. A lot of complaints come from people who do not know how they work and how to unjam them, something that all mechanical pencil owners should learn.
Woodturning pencil kits in lead sizes other than 0.7 mm are uncommon, and most of them take thicker lead, like 2.0 mm. Some penturners remove the mechanism and tip from a 0.5 mm Pentel P205 or 0.3 mm Pentel P203 and use them for their own woodturned pencil. I have not tried it, yet. The Pentel "P20x"-type pencils are the only pencil mechanisms that support this trick. All other pencil mechanisms rely on machined shapes and threads inside the pencil body itself. (The Pentel P203 is not available in the US, but easily purchased from overseas.)
* Sanford ProTouch II 0.3 mm mechanical pencil.
* Sanford ProTouch II, with eraser extended.
* Zebrawood pen and pencil set that I use in the shop, made with Rockler "Long Wood" pen and pencil kits.