Settlement of pigment to the bottom and failure to re-disperse.
Insufficient stirring during storage.
Storage for long duration or under excessively warm condition.
Excessive dilution or dilution with unsuitable materials.
Store as recommended by manufacturer.
Avoid direct sunlight and long storage.
Dilute with appropriate thinners as recommended by manufacturer.
Stir paint to a homogeneous consistency.
Employ mechanical stirring for heavy settling.