I wanted to do some work on a couple frost giants last week. I wanted to start highlighting the skin and was using Reaper’s Golden Skin triad. But the highlight color was all gritty. I emailed a video of the paint (same as below) to Reaper and asked what was wrong with it. I bought it in January 2016, and one or two of the other paints I ordered st that time had the same problem. The response was that it looked like it had been frozen, and to wait for warmer weather to have anything shipped to a cold climate.
They also said that no paint is more than 2 months old when it leaves their factory and should last 10+ years with regular use.
So, buyer beware.