For school work with a fountain pen, go to STAPLES and get their spiral notebooks and filler paper that is made in BRAZIL.
I found that the BRAZIL paper is consistently the most fountain pen friendly paper that I could find for spiral notebooks and filler paper, but not their composition books. And that is despite the fact that it seems to be only 16# paper. Although heavy ink may prevent you from using the back side of the page due to shadowing.
I used to use a heavier filler paper (maybe 20# paper) that worked well with my fountain pens when I was in college, but that was a LONG time ago. And if I can remember, I got that in the college bookstore.
Let me see what I can do for a writing sample for you. It will be on Staples Brazil filler paper.
May take a day or so, as I am getting ready to head out to a party this afternoon.
But just to educate you. Nib sizes are only valid for the specific brand, and not valid between brands.
My Lamy F nib is the same size as my old Parker M nib and my Pilot Metro M nib.
My Lamy XF nib is about the same size as my old Parker F nibs.
But I think I can give you a visual of different width ink lines.
I have to measure my Sheaffer italic nibs, as I do not know its measured width, it is just labled F and M.