MAC Fluidline comes in a small glass pot with a solid plastic lid. If you're careful about closing the lid properly it will take years to dry out. The price is reasonable for department store makeup, too, at $15.00 for a 3 gram pot.
MAC is known for having about a billion limited edition releases every year, and this liner was part of one of them. The MAC me Over collection launched August 25 2011 and int included four limited edition shades of Fluidline including Dark Envy, advertised as a blackened green.
Shade, shown with Painterly paint pot
Sun, shown with Painterly paint pot
On me, it looks more like a dark teal than a blackened green. Wear time is very good, with minimal fading and smudging over a long work day. It's subtle when worn in a thin line, but can make quite an impact if you put it on thick. Highly recommended.