Watercolour + Salt Experiment

Recently, I painted a bird with what I hoped would be a frosty background, only to have my salt effect be completely ineffectual. Which was frustrating, as I had just carefully sprinkled the salt, waited for the painting to be perfectly dry before removing it, and ended up with a very non wintery painting. This made me decide to experiment with the effect of different salts on different paper types, with the salt application occurring at different times, and I wanted to share the results with you all so you can go into it a little better equipped than I did.

To begin my experiment I chose my two most frequently used paper types to try out

• Fabriano cellulose cold pressed watercolour paper, and
• Arches 100% cotton cold pressed paper

and created a grid on each where I could clearly the see the results of each type of salt

• iodized table salt
• fine sea salt
• fine iodized sea salt
• crushed Himalayan pink rock salt
• Atlantic kosher rock salt, and
• generic kosher rock salt 

at the different points of application (how long I waited between finishing painting the swatch and adding the salt)

• 1 minute
• 3 minutes
• 5 minutes

You can see I divided each of those time x salt squares into two different swatches

• Non granulating paint (Winsor & Newton Payne’s Grey)
• Granulating paint (Daniel Smith Undersea Green, Cascade Green, Shadow Violet and Moonglow, and Schminke Tundra Green)

 

 

I did my best to make the experiment conditions as constant as I could, but obviously the amount of pigment and water in each test is inevitably varied, despite my best efforts. I also started experimenting with different granulating colours, which I did for two reasons: one, I wanted to see how the colours I use often would react to the salt, and two, I ran out of Undersea Green on my palette and instead of squeezing more, it led me to test other varieties. This of course obscures the data, but hey! I am an artist, not a scientist. 

Scientist or not, I started this one as you would any experiment, with a hypothesis. I predicted: 

1. that cotton paper would be obviously better;
2. that waiting longer between finishing the paint swatch and adding salt would create a more significant pigment pulling effect;
3. that the greater the crystal of salt, the better the effect, and
4. that granulating paints would create a much more interesting effect. 

I based these suspicions simply on the fact that 

1. I prefer painting on cotton paper as it handles water differently and allows you more time to play with pigment and water;
2. I know that adding salt right away doesn’t create much effect because the page is too wet;
3. a larger crystal would surely pull more water to it and thereby interrupt the pigments more distinctly; and
4. granulating paints have multiple pigments that react with each other to create incredible effects on their own, even without the addition of salt.

What I found was not so clear cut and it became obvious that there is not only one single best paper, salt, or paint, but that depending on your purpose there are a variety that may suit you best. But, for my purposes and my preferences, here are my results and winners:

1. A 1 minute wait time is better across the board (3 minutes gave such poor results that I didn’t even attempt a 5 minute test);
2. Non pigmented paint creates a more interesting effect (this could be because W&N Payne’s Grey is relatively easy to lift from the paper and so when the water moves toward the salt and pulls the pigment it leaves only a very light wash behind);
3. The cellulose paper more easily created the frosty and leafy effect and shapes I love without leaving a dark ring around the salt crystal (although, I do love the more dramatic pulling of pigment on the cotton paper);
4. The cheapest and most basic salt (iodized table salt) created my favourite result, closely followed by iodized sea salt.

 

 

So basically every single one of my predictions proved wrong. The cheaper paper, the more accessible salt, the simpler paint, and the shorter elapsed time all came together to create the effect I prefer. 

Having said this, I think that there is a place for the other results! For example, I love the result of the 3 minute Tundra Green with the fine Mediterranean sea salt (granulating pigment, longer elapsed time, non preferred salt), as well as the result of the crushed Himalayan salt (the effect of the varying sizes of crystals was very beautiful, but very hard to control). And the granulating Undersea Green on the 100% cotton paper looked beautiful at the 1 minute elapsed time; if I was going to paint leafy trees with sunshine filtering through or even sunlight on water, this would be a great option! It immediately had me thinking of the way water sparkles from under the surface while looking up, which made the paint’s name even more fitting. 

 

Right: 100% cotton paper with Payne's Grey and Undersea Green

Left: cellulose paper with Payne's Grey, Cascade Green, Tundra Green, Shadow Violet, and Moonglow

 

While I did receive fairly consistent results, I am now feeling motivated to experiment further. I prefer painting on cotton paper, so I want to figure out how to improve the results on my beloved Arches. I also think that I will need to try the experiment with other non pigmented paints to see if my result is specific to Payne’s Grey. This whole experience has me wanting to create an identification card for every paint that enters my studio, where I paint it in a variety of ways so I can have an archive of how my paints behave, a reference for every paint selection, and learn more about what I like. When I create the card template, I’ll share it on the blog!