Lumps are common enamel defects, which are characterised by rounded raised areas with typically a diameter between 3 to 12 mm.
Scaling
Scaling is a common enameling defect, which is caused by contamination with materials with a higher melting temperature than enamel.
Blisters
Blisters are a common enamel defect, which is characterized by appearance of circular holes & bubbles in a cooled enameled surface.
Fishscaling of porcelain/vitreous enamel coatings
Fishscaling is an enameling defect, which is characterized by small enamel particles chipping off.