Jacques Herbin 1670 Gris Orage (Stormy Grey) is a medium-dark grey fountain pen ink with an intense gold shimmer and sheen. It is an ink formulated for use in fountain pens, and comes in a 50ml glass bottle, made by the reputable French company Jacques Herbin.
Jacques Herbin has been around since the year 1670, hence the name for their premium ink line. The 1670 line launched in 2010 at their 340th anniversary with the ink Rouge Hematite, the first in the 1670 ink series. That ink is a deep red with a gold sheen, and still sells today. They followed up with Bleu Ocean in 2012, and then Stormy Grey here in 2014. The ink comes in a 50ml bottle with a decorative wax seal on the bottle, and a supple wax cap.
It is an ink formulated for use in fountain pens, though Jacques Herbin does put a pretty scary warning on the box about it being highly saturated and how you should clean it out of your pen regularly. The gold sheen is achieved by some sort of fine pigment that is quite visible in the bottle and even in your pen (if you can see in your pen), though we've found that it the Herbin warning is probably a little overstated. You will definitely want to be diligent about maintaining your pens with Stormy Grey in it, though no particular caution needs to be taken as long as you're exercising regular pen maintenance.
Due to the amount of particulate in this ink used to achieve the sparking look, you may experience restricted ink flow in some of your pens. We recommend shaking the ink thoroughly before filling and gently rolling the pen in your hands often to keep the shimmer effect consistent. This will also help prevent clogging. You will also want to be diligent about cleaning and maintaining your pen when using this ink.