Sound decision.............a Medium-long 400nn is IMO a very great pen, that holds much more ink than any other Pelikan.....has great balance. Took me @ 2 years to finally give the nod in balance to the 400nn over the 400.
The nib will be semi-flex or maxi-semi-flex.
Those Are NOT......"FLEX" nibs..................almost flex, and a bit more flexi than semi-flex.
A 'Flex' pen/ superflex has a tine spread of 4, mostly 5-6 or very rarely 7X unless you watch someone spring the nib for you on Ebay or Youtube.
Regular flex like a 200 or 97-82 semi-vintage, '50-65 semi-flex/maxi-semi-flex are part of a 3 X tine spread vs a light line set. Don't push them beyond that.
Semi-flex gives you that old fashioned fountain pens style, with out doing anything. With practice one can do a fancy decender.....but it is not a super-flex one needs for fancy.
Maxi-semi-flex will give you the fancy decenders easier than semi-flex.
Maxi....is pure luck of the draw in the '50-60's era....out side of Osmia where a number in a small diamond is semi-flex and a nib with Supra on it, big diamond or no, is maxi.
Out side of Osmia maybe 1 nib in 5 is a maxi.
You do have to have a regular flex nib....Esterbrook, or Wearever or Sheaffer of the '50-60's or a Pelikan 120/200. That is the base nib for measuring flex in my system. With out a regular flex....and right now if you go to German Ebay you can get a Geha school pen from E12-19.....unless you push the 'Buy Now Idiot' button . It is the best buy for regular flex.
So...mash your regular flex so the tines spread 3 X the width of a light down stroke. 3X is the max or you will spring your nib!!!!!!
Semi-flex takes half that pressure.
Maxi-semi-flex half of that, or 1/4th the pressure needed to mash a regular flex to 3X.
All three are in the 3X tine spread set.
Nails = 1X...no tine spread, semi-nails like a P-75/ modern 400/600 Pelikan = 2X.
Semi-flex is is great enough as is...........have 27.
Being at the well, living in Germany have 16 maxi's....all but the Osmia's luck of the draw.
And I've learned to really like Regular Flex also.....a better nib for Shading inks, in it is not as wet as semi/maxi.
Edited by Bo Bo Olson, 26 July 2018 - 11:43.