Acrylic has the characteristic of a swift drying time compared to oil colors, from a few seconds to minutes, while in oil colors, the drying time takes one or two days on average.
To understand the drying time more accurately, many factors must be considered to understand this paint:
Factors affecting the drying of acrylic:
Dilution of the acrylic color mixed with water.
Adding water to the acrylic color coming out of the tube produces a retarding effect on the drying time; the higher the dilution of an acrylic coat with water, the slower the drying time under normal conditions.
A single coat of 30% diluted color takes between 1-5 minutes to dry under normal conditions.
A thick coat of 30% diluted acrylic color will take 10-20 minutes to dry under normal conditions.
An undiluted pure color coat on a heavy body or artist-quality acrylic will take less than a minute to dry in normal ambient conditions. The coat is undiluted, and only the water contained in the color and pigment evaporates.
The same applies to acrylic colors that come diluted in liquid form.
Environmental factors affecting drying time
Relative humidity conditions, which is the moisture content present in the air, temperature, sun, and wind, directly influence the drying of the paint; this is directly related to the gradual evaporation of the water and liquids contained in the acrylic paint tube or mixture.
Geographical conditions of low humidity and high temperatures
In a dry or desert environment where humidity levels are below 20% and with high temperatures above 30C, the drying time will be swift.
Geographical conditions of high humidity and low temperature
In cold or high-altitude locations where we usually find a high relative humidity level above 60%, the drying time will always be somewhat slow.
Geographical conditions of high humidity and high temperatures
In regions such as the tropics or regions with high rainfall and relative humidity content in the air, 80% of the drying time will be faster than in a cold environment.
Wind and sun
Wind and sun are other factors directly related to the drying time of an acrylic color coating. This is also directly related to the evaporation of the water in the color mixture.
The higher the wind, the faster the acrylic coating will dry. This is why some artists use a hairdryer to dry the layer in a matter of seconds.
The more sun, the faster the acrylic layer will dry. If we put the canvas directly in the sun, we will have a swift drying, of course, understanding that we are not in the Arctic!
Means to paint with acrylic
Retarders: acrylic retarders have the specific function of improving the drying time of an acrylic coating by an average of 30-40% longer than the normal drying time when added.
The delay time of the mixed coating is directly proportional to the use of the acrylic retarder. The more retarder added to the acrylic mix, the longer the paint coat will take to dry. Usually, a normal coat of paint with a 10-20% retarder mix will take 5-15 minutes to dry. A normal coating with 20-30% retarder will take on average 10-20 minutes, and a coating with a higher percentage of 30% could be expected to take more than 30 minutes. However, despite using larger amounts of retarder, the process will not take more than a day to dry completely. It is not huge compared to oil painting, but it will allow many painting maneuvers such as color gradients.
Painting mediums such as the so-called gloss or matte mediums in their gel or liquid forms, although they do not have the primary function of retarding drying but rather of providing a gloss or glaze effect to the color layer, do somewhat affect the drying time by an average of 10-15% additional time, but not significantly enough to be considered retarding in the strict sense of the word. These media types contain organic chemicals that have a slower drying time than water, so a single coat of color with acrylic media will take 10-20% additional time. The thicker it is, the longer it will take.
The choice of painting surfaces is another important factor. The porosity of the surface directly affects the drying time. Porosity is inversely related to the drying time of a normal coat of acrylic paint. The higher the porosity