Dead bubbles

[peterp]

Apparently dead bubbles develop in different stages, the first is just a discoloration. But later traces appear showing the holes (and changes in these) through which the bubbles get infiltrated. We do not know enough about this yet, as it is in the initial stages of development or research.
The bubbles themselves show some differences in the early and later stages, but we do not know yet from when dead bubbles may show.
This is a guess, but some seemingly dead bubbles may not really be dead bubbles, but just are bubbles at or near the surface of the glaze, which might naturally have a tiny hole going through to the surface, after firing; they might get filled with grime or other particles in a relative short time. The dead bubbles we are talking about are deeper in the glaze and develop these holes over a long time.
Currently, the information I got does not say these dead bubbles develop in the Qing dynasty or after how much time exactly. They can exist in Ming dynasty porcelain.