A custard is a styling product that helps give your curls more hold, definition and shine. A custard and gel have the same function, the main difference is the substance. Gels have a 'jelly' and liquid structure. Custards tend to resemble a cream in substance. It is slightly thicker and often comes in a jar rather than a tube. It does not automatically mean that a custard is heavier. You can determine whether a product is heavy based on the ingredients of a product.