What is Gesso and why is it so important?
Many artists have asked themselves this question and have learnt the importance of priming a canvas before commencing an artwork. Not only does primer give your canvas a smoother surface to work on, but it is also the key to maintaining longevity for your artwork. Using oil paint over an unprimed surface can cause the canvas to break down over time as the chemicals found in oil paints can cause discolouration, dull patches and can even cause the canvas to rot. Thankfully we have a range of products on the market that can be used to prime a surface before painting the artwork itself. One that I would highly recommend is gesso.
Gesso is an Italian word that when translated into English means plaster of Paris or whiting in glue. Gesso is a combination of chalk, pigment, gypsum and a binder. It is usually white in colour (though you can also find it comes in black, clear or coloured) and dries stiff with a chalky texture. Depending on the brand, gesso can be more liquidy or thick in consistency. Some apply more smoothly whilst others have more texture which gives the surface more tooth.
Similar to most paints, gesso comes in two grades - student and professional. The difference between the two is that student grade gesso has less pigment and more filler, whereas professional grade gesso has more pigment and is thicker in consistency. Student grade gesso may be less expensive, however this does not mean that it is more economical. Professional grade gesso is quite opaque and has great coverage which means that a little goes a long way. When applying gesso to a canvas or surface, I would recommend painting 3 layers (let the canvas dry between painting each layer) before starting an artwork.
How to apply Gesso
Once you have stretched your canvas or purchased a canvas from the store, it is important to apply at least three coats of gesso to prepare it for painting. If you are painting on a wooden panel, please read my blog post on "How to prepare a wooden panel" here. This will provide more information on the priming process as wood needs special treatment. Some store bought canvases are already triple primed (it will say so on the label) however, I would suggest priming the surface again with your own gesso just to be safe. This is the exact process that I follow and has worked well for me. Before you start priming your canvas, wipe off any dust particles or dirt that may be on the surface. A damp cloth usually does the trick.
Methodically brush a thin, even layer of gesso making sure that you cover every area of the canvas. As gesso is white, it can be hard to see the parts that have been painted and the parts that have not. Once the first layer is down, let it dry completely before adding a second layer. If you would like a smoother surface, you can lightly sand your canvas in between coats of gesso. Remember to let the gesso dry completely before sanding and wipe any dust particles off with a damp cloth before applying the next layer of gesso. Et voila, your canvas is now ready for your master creation!
To summarise, gesso is a really important step that should not be overlooked when starting an artwork. It creates a barrier between the canvas and the paint and other mediums you may be using. Gesso can be applied to almost any surface to prepare it for the amazing artwork that you will create. The more layers you add, the smoother the surface will be. For a more in depth analysis on how to prime wooden panels, please read the blog post on "How to prepare a wooden panel" here.
I hope that you found this blog post helpful, let me know what your process is in the comments below.