BLISTERING: The formation of bubbles or pimples on the surface of finished work. Caused by exposure to excessive heat, significant air movement or improper reduction resulting in trapped solvent.

BUBBLING: The appearance of bubbles in the film while a material is being applied. Caused by any condition that causes air, vapors, or gases to be trapped in the film while it is soft, but after it has hardened sufficiently to prevent the gas from escaping.

CHECKING: Similar to alligatoring, except that the finish is broken into smaller segments. Crowfoot checking is the name given to the defect when the breaks in the film form a definite three-prong pattern with the breaks running outward from a central point of intersection. When the checks are generally arranged in parallel lines, the defect is know as line checking. Irregular checks without a definite pattern are known as irregular checking.

CLOUDY: When a finishing material is turbid, due to the suspension of finely divided solid particles, it is said to be cloudy. A similar appearance in the film is known as cloudiness.

CRATERING: The tendency of a wet film to creep or crawl away from certain areas of the substrate (otherwise known as fisheyes). Cratering is caused by contamination of the paint or surface with silicone, oil or other foreign matter.

CRAZING: The appearance of minute, interlacing cracks or checks on the surface of a dried film or finishing material, due to unequal contraction in drying or cooling.

FISHEYE: A surface depression or crater in the wet finish film. Fisheyes are caused by repulsion of the wet finish by a surface contaminant, such as oil or silicone materials. The depression may or may not reveal the surface under the finish.

GRAIN RAISING: The objectionable roughness of wood caused by the swelling and stiffening of the short, broken fibers on the surface, which more or less stand up due to the swelling or raising action of the liquid coating.

HAIRLINES: Fine lines or incipient checks in the dried surface of finishing materials. Often caused by sudden temperature changes.

HAZE: The dullness of a surface that prevents a clear reflection of light. Usually caused by partial precipitation of one or more ingredients during the drying period. Often removed by polishing or cleaning.

ORANGE PEEL: A pebbled surface similar to an orange skin. Caused by the coating not leveling out completely after application by spraying.

TURBIDITY: A cloudiness in the transparent coating caused by finely suspended matter.

YELLOWING: The tendency of a dried film to take on a yellowish cast with age.

Source: Tim Woolery, vice president of marketing and product development, Gemini Coatings. For more information, visit

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