I personally have two of these pens, I call them "Thin" and "Thick"
The one they are selling here is the "Thick one"
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I've written here using a bunch of different pens.
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As you can see, it is a bit light when compared to other usual means of writing, and it does give the impression it has been written using a pencil.
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In direct light it will reflect a bit and seem more light in color, but this shot was done with a specific angle to highlight this and you won't usually see this effect / have a light directly above and look straight down like that.
Overall, in my experiences, it has been fine on my leuchtturm1917 and I actually prefer the slightly faded color for my eyes.
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random page of notes about a change of information with the government
I have been carrying these two pens with me for the past 1/2 year and obviously they won't ever dry (like the felt tip) or break (like the H pencil, NOT shown here because I didn't have a sharpener) or run out. But they are a bit light in color, acceptable (for me) in everyday usage. I haven't actually written hard for any of the photos here, the underline is a little bit harder just because of the way you draw one.
Hope this helps!
P.S. if this happens to be the only pen on hand when you need to sign an official document, the person receiving it WILL get mad at you and suggest that HOW DARE YOU use a pencil to sign something :)