Cracking or crazing in acrylic and how to avoid it!
Do you just get so wrapped up in a painting or craft or whatever that you can loose yourself? Over recent years my art has been my salvation and best way to escape the stresses of everyday life but sometimes, even though I have been painting for over forty years, I end up with some cracking if I use acrylic. Acrylic is a great alternative to oil for so many reasons but if there is too much water it can cause problems. The crazing is due to the top layer of the painting drying faster than the bottom layer. The top layer forms a skin and hardens whilst stretching but the underlay is still wet and trying to dry. The top layer literally cracks through this stress. Don’t try to paint over it as the paint will eventually fall off through lack of adhesion.
If you have to remove paint, try gently rubbing the surface around the cracking with a non abrasive sponge under a running tap or soften the paint by floating a small amount of water on top leave for ten minutes and scratch off gently with a pallet knife.
Leave the canvas to dry thoroughly before use.
The good news is that there are a number of ways to prevent this….
Reducing the amount of water….do not add more than 30% water to the paint.
Binder, available as liquid acrylic polymer emulsion or a gel, gives the paints their adhesive qualities, binding the polymers together. Too much water weakens the binder and results in cracking. There is a general consensus amongst brands that adding up to 30% water is still ok. If you want the paint more fluid then….
Add medium…
There are many mediums, gels and liquids on the market and so many brands from gloss, matt, pouring medium airbrush medium and so on…Each of these is made of a binder. Add to the paint with the water and it will stop the cracking.
High quality paint and low quality….
High quality artists’ paints from brands such as Winsor and Newton, Daler Rowney, Golden, Liquitex etc have more pigment and are generally better quality so more medium can be added without reducing the intensity of the colour. Some student quality paints and cheaper acrylics contain a lot of binder and less pigment so results are not as good.
Be careful using acrylic ink…
Daler Rowney FW acrylic ink is a favourite artist’s quality ink but has to be used in the right way or cracking is inevitable. I have had several paintings- like the one shown here- where the ink was put over wet acrylic paint without letting the substrate (bottom layer) dry and have had to carefully remove the paint back down to the canvas and start again. Very frustrating!
Temperature, humidity and fans…
Fluctuations in temperature and humidity can cause some cracking. Working in the humidity of Bangkok was ok as long as I didn’t pump up the air-conditioning and let paintings dry naturally. Fans blowing directly onto the artwork can also cause cracking as he top layer dries too fast.
Don’t varnish until the painting is completely dry…
All sorts of problems with varnish ( I am a bit of a perfectionist which does not help). Let the artwork dry completely for three or four days first if it is acrylic or mixed media….
If you want to find out more take a look at https://www.winsornewton.com/uk/discover/tips-and-techniques/other-tips-and-techniques/five-essential-acrylic-mediums and https://www.liquitex.com/wp-content/uploads/sites/42/2018/12/LIQUITEX-PRO-MEDIUMS-BOOKLET.pdf
Preventing this cracking is relatively simple if you remember to follow the rules……