HELLOOOOO yes i am fountain pen people!! And I am happy to talk your ear off about fountain pens and inks :D
For shimmer inks, Diamine is really well known for well-behaved shimmers. I have a bunch of theirs, they’re always rarely clog and are generally well priced and a great all-around option.
I am also really enjoying Wearingeul Inks! They have a lot of pretty shimmers (with great names XD) I’ve used their “The Great Sage Heaven’s Equal” for a while now with no problems.
Robert Oster is another brand with, in my experience, good shimmers.
Sailor doesn’t have a lot of shimmers, but they have a lot of gorgeous, very well-behaved inks. Their dual-shading inks are definitely worth checking out. (I am at the moment kinda preferring dual shading to shimmer, partially because they’re easier to clean out of pens and less likely to clog.)
Troublemaker Inks can be hard to find but they have some GORGEOUS inks, both intense colors and cool dual-shading. They make my favorite muddy green - Hanging Rice.
If you want to check out in-depth ink reviews, Mountain of Ink is hard to beat. A lot of people do ink reviews but I appreciate MoI’s consistent review format and the sheer number of reviews she’s done. That said, you will definitely end up with a terrifyingly long shopping list, which brings me to my next point…
Vanness Pens has the best selection of inks in the US. They’re my go-to for inks! It’s pretty much always worth it to buy a sample before committing to a whole bottle.
Vanness Pen Shop Supplying writing instruments, fountain pen inks, stationery, education, custom engraving, and unique gifts since 1938. Thi
Also good: JetPens, Yoseka Stationery, Enigma Stationery. (Avoid Goulet Pens, they turned out to be super fundamentalist Christian and one of the pastors of the church the owners helped found compared LGBTQ people to murderers.)
(Also avoid Noodler’s inks, the owner is racist, antisemitic, anti-vaxx, and his inks sometimes damage pens.)
Inks I Have Issues With (Aside from the Aforementioned Noodler’s):
De Atramentis copper shimmers: so pretty. Sooooo prone to clogging 🫠 they’re utterly gorgeous but they’re also the only inks I have used which instantly clogged my TWSBI pens. They’re very pretty in dip pens but don’t waste your money on them for fountain pens, imo.
Ferris Wheel Press has gorgeous packaging but they’re also kinda notorious for being dry inks. A lot of people feel they’re more about the packaging than the actual product (influencer brand ugh.) Also they’ve used AI, their pens are repackaged Fuliwen pens that they charge too much for, and they are doing a Harry Potter collab -_-
And now if you’ll excuse me I opened up Vanness to get the link and now I need to go peruse the fall collection of Midori stationery - my greatest weakness XD