Jargon.

This will be an ongoing post where I take some terms I'm going to use and define what they mean to me.

Bleed - where you can see an echo of your writing on the reverse of the page.  At best it's annoying, at worst it will mean that it will mark pages through a few leaves. Standard photocopy paper is among the worst for this.

Cartridge Converters - very useful things these, will lead to ink on hands. But you can use other inks in your pen, and there are some very pretty inks out there.

Feathering - This is where you get blurring around the edges of letters due to the paper being too absorbent or the ink being too wet or a combination of both.

Fountain Pen Friendly Paper - paper that exhibits not a lot of feathering, ghosting or bleed.

Ghosting - where you can see some echoes of your writing on the next page, related to bleed but usually you can use the reverse page.

International Standard Cartridges, Cult Pens explains it quite well; these are the most commonly used cartridges, most of my fountain pens use them, except those that don't like Lamy (though there is a German company Online who have cartridges that do both, I will be stocking up again).Not all pens who take International Standard Cartridges take the long ones but they all can take the short ones.

Nib Width - this is such a messy thing.  If in doubt, and the brand isn't Japanese, the nib is probably medium.  Back when I was learning how to Calligraph (yes I will talk about calligraphy in a proper post and link it here) I didn't know that standard cartridge pens came in anything other than medium, I certainly didn't know they came in left-handed.  There are many nuances within the widths.  When you first buy a pen I would suggest looking at your handwriting, if you write small, get a fine nub, if you have big writing get a broad nib.  I would also suggest getting a few sizes and seeing how they suit you and your paper..  I often use a broad nib to illustrate the page that I use for the beginning of a month and use flourishes and enjoy it but every day extra fine or fine are more my mileage.

Test page: It is often useful to have a page at the back of a notebook to test pens and paper, write the pen and what ink you're using, some ink is less watery than others but often you will find that a particular pen puts the same amount of ink onto the page.