#Pouring paint on canvas skin#

However, when a very thick coat of paint dries and the volume of paint begins to shrink due to evaporation, that stress level can exceed what the dried top coat can handle and cause cracks to form. This causes stress.Īcrylics were made to handle some stress, which is why they are considered more durable and flexible than other types of paints. When the paint is too think, there is more contraction happening as the water and solvents evaporate and move out of the paint. The paint underneath takes longer to dry. With very thick paint, as with thin paint, the top layer of pain dries the fastest and forms a skin. Water and solvents are what makes acrylic paint “thick” looking compare to when it is dry. Paint that is drying is loosing it’s water and solvents due to evaporation. Using acrylic pour paint that is too thick can have a similar effect that thin paint has. The paint below will then dry and contract sideways, expanding the crack. The stress of the bottom coat volatiles evaporating can cause the top to “buckle” and break, which is why you see cracks.

#Pouring paint on canvas skin#

Having less binder reduces the stress that the semi-dried, but uncured, top skin can handle. With thin paints, there is less binder to hold the paint together when dry. The plastic/polymer binders, which hold dried paint together, accumulate on top and form the skin during the first part of the drying process.

With thin paint, the top coat tends to dry very quickly. Too much of either will increase the potential of cracking. Small amounts will not have enough of an effect on paint and are valuable to control consistency. Because acrylic paint is water soluble, these additives also tend to break down the binders in the paint. Very thin paint mixtures, especially those diluted with excess amounts of water or alcohol, are prone to cracking because there is not enough binder in the paint, and/or paint medium, to hold everything together once driedĪlcohol and water do not contain any binders. The consistency of your paint has a tremendous affect on potential cracking when the pour paints dry. Once you understand why cracking happens, you’ll be better prepared to reduce the change they happen again in the future. As I mentioned before it is bound to happen to all artists. If you are reading this blog you have, most likely, already had a painting crack. Related Questions In Depth Look at the Causes of Cracking.In Depth Look at the Causes of Cracking.