I rant about various stages of flex that a nib can do quite a bit.
As a 'noobie' the first thing we Don't Do, is spread the tines like doing Olympic Splits.
Richard Binder's com is the bible of nibs, pens and good advice on inks. He wrote an article of how to easily spring your nib...so you need $$$$ to repair it.
I don't know that brand....I know a tad about Swan...had a Wyvern that had a very nice superflex nib. I was chasing an English Swan very slowly and after 6 weeks had decided on a '50's lever pen, when I ran into a German no name War pen with a Degussa superflex nib. I had been after a superflex Swan.
Having semi-flex and maxi-semi-flex had no problems with finding the border of how much tine spread that nib had....5 X...so mostly I only go 4 X.
If you read that Article by Richard....it will help you understand maxing a nib is bad for it....good for those few who can repair a sprung nib.
Let's keep that nib to start with at semi-flex to maxi-semi-flex....3 X tine spread of a light down stroke.
In we don't know if it is superflex or semi/maxi-semi-flex..pressure to 4 X...does the nib seem tight...if so stop.
If not you have a 4 X tine spread.
Again very lightly press the tines into the paper as you draw a line...did it expand with any pressure....even if it didn't stop now at 5 X. Try to keep your use at 4 X and less.
One of the odd things one of the good posters linked to a '30's Waterman advertisement. It appears they were interested in max tine bend...and only 3 X tine spread.
We all of us have been spreading tines that might well have only been designed to do 3 X all the way out to 7 X.
Now what other pens do you have....it could be possible but I doubt it; on general principals, you could have a semi-vintage 'mid '90's to 60's. That could have a springy 'true' regular flex. The nib that use to be issued much of the time.
Most of the new nibs are nails and semi-nails in they bend less and have to be repaired less....mid '90's to now that is normal outside of a few companies the Pelikan 200 is still good, the 400/600 not; being semi-nails.
Why is this important? I jury rigged a system to talk about flex.
Nails don't have tine spread....1 X. Semi-nail when pressed by a noobie or a weight lifter gets 2X tine spread over a light down stroke. Noobies are well known to be Ham Fisted or worse...Jack Hammer Handed.
It appears you have a controlled Hand. Very nice script too.
I call the 'true' regular flex, true in most pens are semi-nail or nail nibs when issued. Some have come from that and the first time they run into the old regular flex...think it semi-flex. It is not.
Outside the 200 just about any of the 'true' regular flex nibs in semi-vintage....before late-middle '90's....70's- or Vintage '60-50-30's and perhaps even earlier depending on where in the world the company was....most made a regular flex nib.
It if well mashed spreads it's tines 3X a light down stroke......not something to do often....That is a max of it's tine spread. And it take a hell of a lot of pressure to do that...and is not comfortable to write that wide. It is just to set a pressure level for the rest of the nibs that have more flex. 1/1 so to say.
Semi-flex was common in the (could well be before) '20-40-60's. It needs half the pressure of a true regular flex (1/2) to spread it's tines 3X....(It is very helpful to have one of those true regular flex nibs....for that and they are a nice ride...and good sometimes better for shading inks...in semi-flex is often a wetter writer due to ease of tine bend.
Maxi-semi-flex takes half of that of a semi-flex or 1/4th the pressure needed to mash a true regular flex to three X.
These three are all 3 X tine spread max.
Outside of Osmia...Diamond = semi-flex, Supra = maxi-semi-flex...it's all luck of the draw and I expect the Pelikan 140 to be semi-flex. I have in Semi-flex, three '50-54 '400's; an Ibis ('40's early '50s'), 400nn ('56-65) and a 500 ('51-54) in maxi-semi-flex...and that is just the ones in Pelikan.
I have some 26 semi-flex (1 English Parker) and 16 maxi-semi-flex. Luck of the draw.
Superflex spreads it's tines 4, 5 or 6 and seldom 7X a light down stroke.
Superflex is more complicated than my simple system...but is helpful to noobies or folks just getting into the more flexible nibs.
Easy Full Flex....half the pressure needed to spread the tines of a maxi....or 1/8th of a true regular flex nib to spread it's tines 4-5X...I've one, and I've a 5 X that I do not take over 4 X....in I don't want to spring the nib. Read that Bender article.
It's an eye opener.
Those who can write well, are more interested in how quick the nib returns to a narrow line than how fat you can make the nib spread it's tines.
It is very hard for me to tell you what it feels like when pressure of how wide does this nib go, has been reached.
I had worked my way up the flex ladder so had an idea.
Even if you do have a 7 X nib...you are too new to use it well and not spring it. Try to keep it at 5 X or less tine spread. I am not an expert. I do have 5-6 of them.
I'm too lazy to work at learning to draw the letters...just an occasional fancy decendere.
Wet Noodle...half the pressure of the Easy Full Flex...or 1/16th the pressure needed to mash a 'true' regular flex. I have two. I don't need any more of them...In I do not work the nib...I do not practice drawing the alphabet from a Calligraphy book.
Weak Kneed Wet Noodle...even less pressure ...I don't have any of them.
Many a nib has been ruined by idiots on Youtube making a nib do Olympic splits....I have a nib that I can take to 5X that I only take to 4 X. I have a nib I can take from xxf to BBB....
I sweat to get my Hand so light as to make it draw a line at XXF.....and I stay at a max of BB.
My Hand is not as light as it could be that Waterman 52 Wet Noodle . Lots of times I just grab it and scribble normal with out trying fancy strokes. It writes to an F. With the right ink and paper I like making a fancy capitol L. the classic English Handlebar mustache.
I do have some dip pen nibs that make a wet noodle look uncooked.
That is what I suggest you do....buy a holder and a few dip pen nibs to practice with. If you break one....so what.
There you have a beautiful pen, with a grand nib, and I'm telling you to put it aside until your skill matches the nib.
You if it is a superflex have to practice drawing letters.
What if it's only a semi-flex..... . Then it should if you don't go pressing it all the time only take you three months to lighten your Hand to worry about buying some dip pens.
I like that flowing capitol L.