Thanks, Amberlea. I think you said you bought some of the bottled Thornton inks. Have you had a chance to try those? I am betting they are not the same as these cartridges.
I have been trying to pin down the Lamy cartidges whie they are still for sale for cheap on eBay. In my experience, it would be rash to apply the below to the short international cartidges or the bottled ink. Here is the latest for the Lamys, by color. I will mainly address flow, as these inks often do not.
Really impossible flow in a Wing Sung 500 so I tried another 500. Worked fine at first but not for long. In a Waterman 1900 (also a fine nib) it usually started but skipped in such a way that it looked like I was writing in dotted lines. (Yes, these work upside down in some Watermans -- though NOT the first generation Phileas.) Worked fine in a Safari and a Reflex. I write a lot of book reviews for the Mathematical Association of America and there I try to indeify what audience the book might best fit (which is often not the intended audience, and sometimes does not exist). Here I could only suggest this to someone who wants charcoal grey ink and has a very free-flowing pen to use it in. For me the question is whether this is usable enough to justify buying the assorted color packs to get the red cartridges, figuring I might be able to also use up the black in some low priority context. But then right now the reds are still at a good price even if you throw away the other colors.
I like it but the color is not that diferent from Waterman or some Parker reds. It is much richer than the sample of bottled ink Amberlea posted. However, it is really cheap if you can use the other colors in the assortment as well. This was somewhat balky in a Wing Sung 500 but OK in a Wing Sung 840 and a Parker Frontier. As noted earlier, it was hopeless in a Reflex.
Worked great in a very fine-nibbed Hero 50 and in Parker Frontier, Beta and Reflex pens. No trouble with it and it is generally a rich dark blue though not entirely consistent. You can buy just the blue at about $11/100 cartidges which is a steal. Highly recommended!
So-so in Jinhao 699, good in an old A&W Sizzle Stix. Very dry in one Parker Frontier, OK in another, and balky in a Beta. Always useable. A dark blue-purple. Good enough to use if I buy more assortments to get the red.
Fine in A&W Marquis, two Wing Sung 500s, and a Parker Reflex; balky in a Frontier. The color is all over the place from a blue-green similar to European green inks to a very dark turquoise. Not bright except when it is at it lightest color. It usually does not look like any other turquoise from a pen manufacturer, though I am sure that among Diamine, Noodlers, and Private Reserve you could probably match anything;-) Works well and so is a posssible utility ink to use up when you don't care what the color is -- or would like to be surprised by the color!
Blue is a keeper and red worth fussing with. Purple and turquoise are useable. Black is hard to get along with and does not offer much in return. I would say it's the grey sheep of the family;-) All are ridiculously cheap in quantity.