Robert Oster Green Diamond is another green from Robert Oster. I always hear people talking about Robert Oster blues, but I think he makes some great greens as well. I purchased my sample of ink from Vanness Pens.
Green Diamond is a medium bright green with some shading and sheen.
When pooled, the ink has a dark pink sheen.
Dry time: 25 seconds
Water resistance: Low
Show through: Medium
On 20lb copy paper there was feathering in all nib sizes, but other than that it did well.
I used a Conklin Durograph Forest Green with a broad nib on Tomoe River paper. The ink has an average flow, but I didn't have any issues.
Overall, the ink performs well and has a decent dry time. The color is nice, and there is some great shading and sheen.
Disclaimer: I purchased this ink myself, and all photos and opinions are my own. There are no affiliate links on this page.