Saturday, August 6, 2016

Getting Even Watercolor Washes

Blog reader Kaos No Kamisama asks:

"May I ask how do you get your watercolor to spread so evenly on the paper? I always end up getting different concentrations of pigment or those pesky dark corner-concentrations."

Kaos, in my experience the evenness of watercolor washes depends on "The Four P's": the paper, the pigment, the prewetting, and the pitch (or tilt) of the board.

If the paper is gelatin-sized to accept the paint, the wash will spread more evenly. All proper watercolor paper should have sizing in it. Also, the paper should have some tooth, but not so much tooth that you can't get the paint into all the little valleys. Smooth paper (also known as plate finish or hot press) tends to take washes more unevenly than rougher, cold press watercolor paper. The paper should also be absolutely flat, which is why you want heavyweight paper, or a block, or stretched paper, which won't buckle when it's wet.
It's important to mix up a generous amount of paint and use a big brush, so that you don't run out of it in the middle of the wash. Also, the type of pigment can affect how a paint disperses. Finer organic pigments such as phthalo or quinacridone will disperse more evenly than some relatively granular inorganic pigments such as viridian. Also, paints vary in how they're formulated. Some have a dispersant additive that makes the pigment flow more evenly.

Prewetting an area with clean water before you add the pigment wash will aid dispersion. You can do this with a big, clean brush, applying the water evenly to the area where you want the wash. It should be slightly damp with no puddles. Then when you add the wash it will go down more smoothly. This method is especially good for a large area without too many detail cutouts, such as a sky. Painting a sky over a dampened paper also allows for the introduction of soft edges, especially around clouds.

Finally, and most importantly, the pitch or tilt of the board allows the wash to advance by gravity down toward the buildup of the "bead" of paint. You can keep advancing the bead downward as you develop your wash. The gravity will keep the wash from puddling backward (also called a backrun). Obviously you don't want the board to be so steep that the water breaks through the bead and drips down the board. The tilt the board can be anywhere from 10% to 40%, but it shouldn't be any moreHere's a previous post with photos of Ogden Pleissner's palette.
tilted than necessary. As you practice you'll notice that more watery mixtures will drip more easily than thicker paint mixtures. The need for a variable pitch to the board is why watercolorists need easels that can be set up at any angle, and ideally adjusted on the fly.

There's a lot more information about laying washes on the excellent website "Handprint"
My video "Watercolor in the Wild


Glenn Tait said...

It is interesting how the pitch or tilt of the board has changed so dramatically in the last number of years. Many watercolourists like Joseph Zbukvic, Alvaro castagnet, Herman Pekel, David Taylor and others seem to be working on close to vertical boards now and using (designing as in Castagnet's case) longer handle brushes.

An example of this can be seen on an earlier Gurney Journey post.

Eugene Arenhaus said...

All very practical advice, James.

I could add that to get an even wash, it is best to build it in oblique strokes with a round brush, leaving a jagged edge at the bottom to allow for a series of beads, rather than a single pool of paint. Horizontal strokes and/or a single pool of paint has a high probability of producing bands in the wash, which oblique strokes help a lot with. The brush must not be allowed to run dry for the full duration of laying down the wash.

It is also not advisable to let any of these beads dry out. That is guaranteed to produce bands or backwashes. However, an uneven wash may be salvageable if you immediately repaint all of it again with higher-concentration paint. It will re-wet the previous wash and somewhat hide the flaws in it. The drawback of this method is, of course, that you end up with a darker wash.

James Gurney said...

Eugene, you're totally right, I should have mentioned it. In the "Handprint" post by Bruce MacEvoy linked in the post, he also talks about scalloping or tiling the strokes and painting up to the bead as you lay down the wash.

Eugene Arenhaus said...

Thank you, James. Painting 500 owls mostly in watercolor does make one remember to do these things. :3