Builder In A Bottle aka BIAB(tm) is a range of soak-off builder gels ideal for creating strong overlays and used as a strengthening barrier for natural nails. The GelBottle Inc was the original inventor of builder in a bottle and its patented, best-seller formula that is loved by nail techs across the world. The best part of BIAB(tm) is that it's an all-in-one primer and base, which helps to add an extra layer of protection to the nails.