The putty joint contains a series of chemical additives, aggregates and special colors in the form of grains that attribute a color to the putty joint.

In case of bad stirring, some grains are not broken and, if they come to the surface and "explode" during re-jointing, the above phenomenon is noticed.

Remember that, with the addition of adhesive strengtheners, there is a possibility of a slight change in the color tone of the joint and the appearance of more gum texture of the joint.