Refers to a milky appearance on the surface of a paint film and is usually a result of an incorrect balance of thinners in the paint formulation or the rapid evaporation of thinners from the coating.
Coating defect: haziness of coating surfaces caused by the exudation of a component of the coating such as oil plasticizer, or noncrosslinked coating constituent when the coated part is exposed to a cycle of heat, humidity, and cooling.
Where the colour of a dried paint film appears to be hazy. Blooming is caused by moisture trapped in the film and is usually down to ambient conditions. The effect can be commonly seen with decorative paint s, where the substrate the paint has been applied to is not fully dry, or where exterior paint has been applied in damp conditions.