"Stub" nibs seem always (**) to be ground flat not only on the bottom and end, making the angle that contacts the paper and gives directional line variation, but also on the top which never (*) contacts paper.
When customizing an ordinary ball-tipped nib to make a stub, why go through the extra step of grinding off the top?
I know it is not necessary for writing to flatten the top/back of a round nib, nor of a CI: I have a cursive-italic nib, customized from a broad, that is an EF for writing upside-down, rather the opposite of flat.
Yes, I know that a "stub" and a "cursive italic" are distinguished categories. If the distinction is relevant to my question, please elaborate on how. Otherwise not.
And I also know that the "angle" I referred to above is eased or rounded on a stub nib. If that is relevant to my question, please elaborate on how. Otherwise not.
I would rather not hear a bunch of guesswork answers. Those I can make up for myself. Please wait for someone who actually knows.
Would it not be both less work to leave the backside of a stub round, and slightly beneficial in providing a (vey slight) extra bit of ink buffering very near the point of delivery?
Why is it done?
(*) "never" in its regular use a a stub nib. The possibilities for using the reverse of a nib are interesting. That's a different set of questions I am not asking now. I just want to know why stubs have those possibilities ground off.
(**) "seem always" because every stub nib I have examined, and every close-up photo of a stub nib I have seen, and the instructions I have read for grinding a stub, all show this feature. But I have not done a survey. If there are some stubs that do not have the back ground off, please show a picture. In any case my question remains for those that are ground off: Why?