An unsufficient leveling during the drying process, lead to numerous possible film
defects, such as orange
peel, brush marks...
This phenomenon, caused by gradients in temperature, concentration, viscosity and
density, induce a non-uniform surface tension in the coating.
Leveling is the ability to form a smooth film when paint is drying. This
property depends on surface tension which drives flow of an uneven liquid surface
to a smoother one to lower the surface energy.
The use of surface modifying additives, especially
surfactants or rheology modifiers,
is a possible way to enhance the leveling property, and thereby improve both appearance
and performance of your paint.