Binder can separate occasionally from some of the denser pigments. Our paint tubes are filled from the bottom, then crimped and boxed to ship. Once out of the box, they’re flipped to hang by the cap on display racks, so if there was a little air space left in the bottom of the tube after being crimped, a dense pigment can gradually settle to the bottom and push a small amount of excess binder (gum arabic) up to the top. You can squeeze out and discard any excess binder without affecting the performance of the paint.