Swelling of the intonaco provoked by pieces of lime in the mortar that were not properly slaked. Also see lime crumb. Filippo Baldinucci (1681) and Giacinto Carena (1853) registered the phenomenon with the term untacking, that means “the breaking open of the intonaco for certain lumps of lime that were not well-slaked, or of another material, those that when they swell, the surface rises and falls together with a part of the intonaco that surrounded the area, round and caved in the center, as happens sometimes in wanting to remove a bullet planted into the intonaco.”