First of all; when you first apply it to your lips it is very slippy, so I had trouble spreading it over my lips neatly. It kept bleeding [yes, I used lipliner] outside my lipline, so I had to keep cleaning up smudges as I waited for it to dry. I also found that this is a pretty slow product to dry, so don't wear it if you are in a rush.
When the formula is dry I was impressed with the pigmentation; Lip Tar is as vivid as a lipstick. However it does transfer easily; I sipped a drink and ate a sandwich, and the product went everywhere - much more than my other lip products do. To be fair there was still colour on my lips, but the shade was less vivid, and once again it had sneaked back outside my lipline.
So whilst I love the pigmentation of my Lip Tar and will continue to wear it on occasion, I doubt that I'll ever buy another one as I disliked how messy they are; especially to apply since it doesn't dry quickly.
The official OCC site...
[UKers] You can buy OCC through Selfridges site.