Watercolor Paint Ratio

Understanding watercolor paint ratio is very important to those who want to be a professional watercolorist or at least to get better at it.

This may come as a surprise to you, or you may well have never given it a thought. For sure, you have never read about it in your favorite magazine or book.

This is going to be our little secret. Paint chemist’s actually design colors to have a certain paint to water ratio. “Never gave it a thought,” students reply as they just splash water on to the colored pigment to paint. If you produce a solution that is too saturated with paint, you have lost the ability to create sensitive nuances of luminous color. Add too much water and you will create a weak, light wash.

How do I know this to be a fact? I asked questions when touring paint factories in Europe.


Drop a round bead of water on your palette.What do you notice? It is not flat; it is a domed shape.

Now put another, both about size of a quarter (1 inch +-) space them about 3 inches apart.

This will be a good time to show you images; I think you might learn more if you do it yourself.  So no images from me.

One is going to have paint in it (shortly); the other will be a gauge for comparison.

Take a round, damp brush loaded with say Cadmium Yellow. No, let’s make that Cadmium Red. Now, very carefully touch the top of one of the beads of water discharging the paint; don’t change the shape of your dome. If you by chance do change the shape, you are going to have to start again. I forgot to mention the domes are formed by the water molecules producing surface tension on the surface resisting collapse.

Ever filled a glass with water and noticed the water level is above the rim (surface tension). Now you should have one dome with paint and one without.

Load the brush again and repeat adding color to the colored bead –  CAREFULLY.

Do not spread the bead around. Repeat and repeat until the painted bead slowly looses its surface tension and starts to flatten out. Compare it to the non-painted bead. See the difference; the paint has broken the waters surface tension.

When the painted bead collapses, the water to paint ratio is “unsuitable.” Any wash with this mixture will be flat,  dull, and opaque.

This is what you do now: Add a little water to reproduce the dome effect.  You will now have the most concentrated wash possible with that color and still have luminosity. In other words, you will be using the ratio that developed just before the surface tension was broken.

If you feel strange doing that exercise, imagine me in a lab, being watched by a couple of paint chemists. I had to buy their lunches to boot.

Re-cap.  A good water to paint ratio exists just before the dome breaks down. The paint is suspended in a grand reservoir or water that can discharge an abundant deposit of color to the paper, giving you the greatest luminosity that the chemists could produce by adjusting all the different ingredients that went into that particular color.

This obviously is not used in dry brushing.

I had no idea of all the work that goes into producing a quality product.

The analysis and experiments that are conducted on a daily basis just to keep up with the different formulation of chemicals (nothing ever stays the same) was very surprising to me.   The large chemical corporations who supply dry pigments to various industries constantly change their formulas due to demand, cost-cutting changes, supplies change (again nothing stays the same).  The auto industry has a large say in what pigments, what colors are to be produced, followed by the plastic industry.

The watercolor manufacturers are way down on the pecking order.

SIDEBAR. When I hear artist’s say, “I have always used this brand or this color for the last 20 years, and I just don’t like to make changes.”  I just smile.

There are many new color changes that you may have never tried.  This will be covered later in one of my future “Newsletters”. You can subscribe to my newsletters at the bottom of this page.

Now, let’s mix paint the logical way – working with a wet brush.

Place two small blobs (size of a bean) one of Burnt Sienna and the other Ultra Marine Blue on the palette.  Remember how we added paint to the water, let’s do it the logical way adding water to the paint.  It will not take more than a few brush loads.   Slowly mix the two colors by adding water, don’t smear it all over the palette.  Keep it in a tight controlled area. Stop adding water as soon as you see the raised puddles mix together.  Using your brush, scoop up as much of the mixture and apply the wash into a 2- by 2-inch square.  Leave it alone and let it dry.  The paper must be flat.

The wash should rise above the surface of the paper.  No messing with it;  just apply, and leave it alone .

Working with a damp brush:

Now take the same two colors, and mix with as little water as possible; you can smear it all over the palette.  You will now have a high paint ratio to water.  Now plunk this sticky dark mixture into another  2- by 2-inch square, right next to the previously painted square.  Let it dry.

The difference between wet brush and dry brush should be evident when it dries.

  • The wet brush method produces a more luminous result.
  • When you need a lighter value of a darker statement, just add or water.
  • But here is what I learned talking to the chemist.  Don’t think for one minute you can use that sticky dark mixture that you spread all over the palette with the intention of spreading it out thinner, which will work but produce less interesting results.
  • They went on to say, most artists would not work with that dense of a mixture that we just mixed.
  • Looking through the lab instruments, it appears the less dense the examples the more subtle the differences, but they were there.

A lot more to tell about paint behavior in a later Newsletter.

What do you really know about the three colors that were the stars in the previous examples? Namely, Cadmium Red, Ultra Marine Blue, and  Burnt Sienna.


Pigment Red 108. This is a very popular color; it runs from moderately dull to very intense color,  orange to deep red. The paint covers well, easy to handle, and active wet in wet.  Blossoms readily when water is dripped, thrown into a damp painted area. Although opaque, it dries to a much more transparent look in tints.

Don’t use as a glaze; it has a strong, dense consistency. Cadmium Red is expensive.

The perfect “opaque” companion is Cadmium Yellow, PY35, which makes a good clean opaque orange. It can give you finely dispersed washes or very grainy washes (depending who makes it).  And, there is a ton to choose from.  Winsor Newton,  Daniel Smith, Holbein, Rembrandt, and Maimeri Blu all make at least three tubes each of variations of Cadmium Red., light, medium and deep.

Cadmium Red Deep, is not friendly with other colors too much (again depending on who made it).

The range of color is vast.

Why? Because during manufacturing, the color is adjusted (remember the chemists) by precipitating Cadmium sulphate under differing conditions and with varying proportions of sodium sulphide and selenium.

Please don’t ask me what that stuff does; I don’t know. This much I do know, if you think the tube of Cadmium Red you purchased a year or two ago is the same as this year’s model, duh. When it is mixed with Burnt Sienna, PR 101 produces a hot rusty Brown.

When mixed with Cobalt Blue, PB28,  which is a very neutral blue, it is also a weak color, always add other colors to it slowly.  In this case red, a dull purple will result (depending on your choice of red).

When mixed with Phthalo Green, PG7,  they are almost opposites on the color wheel. It creates a useful range of natural colors, which is a good choice for winter landscapes, warm rich grays.

When mixed with Ultra Marine Blue, PB29, this blue has a purplish bias.  Cadmium Red leans towards orange, so expect a restrained dark purple to say the least.

Cerulean Blue, PB35, leans toward green.  Cadmium Red leans toward orange.  So when mixed, you have blue, green, red , and orange.  By mixing four colors, however, you are going to get mud.

I never get mud (that’s because they don’t get mixed hard together).  Bearly mix them together, just like two strangers meeting for the first time, restrained.  You will get a nice mottled effect.

When mixed with Raw Sienna, PR101, it will produce a grainy quality. The mix gives a muted but glowing deep orange that would be useful in still life, landscapes, and portraits. Frankly, I know very little about portrait painting in watercolor, but I happen to know someone who is an absolute master in portraits, still life, and landscapes. Her work has been placed in the Royal Collection in Winsor, England and received numerous awards nationally and internationally over the years exhibited in England, Sweden, New York, United Nations, Mexico and Canada. She is a signature member of the American Watercolor Society, Canadian Institute of Portrait Artists, Canadian Society of Painters in Watercolor, and the list goes on and on.

So stay tuned, you will be visited by her shortly.

Cobalt Violet, PV14 and PB28.  Mixed with PR108 gives unusual soft and subtle pink. Just thought it looked like it might make a nice color for portraits.

Winsor and Newton’s group of Cadmium Reds lean towards orange, warmer than any other manufacturer.

Daniel Smith group of Cadmium Red tend to Bronze at full strength.

M. Graham has a good deep red cadmium which is staining and semi-opaque.

Some of the inexpensive brands of Cadmium Red such as Da Vinci, Rowney, Lukas all have a lighter color and a white tone.

Could have added brighteners.

Seven manufacturers at least, make Cadmium Red Deep.

In my opinion the following are not quite up to standard of the rest of the group:

  • Holbein – Cadmium Red Deep
  • Da Vinci – Cadmium Red Deep
  • Senneliar – Cadmium Deep Purple

Winsor & Newton’s Cadmium Red is a beautiful color, lightly warmer than other brands.

For Cadmium Red Orange, I did not like the following:

  • Da Vinci — Cadmium Red Light
  • Blockx — Vermillion.


Color index PB29GS or PB29.

All the following manufacturers produce a good color in my opinion.  So take your pick based on the following:

Winsor & Newton –  (make Both)

Rembrandt – (make Both)

Daniel Smith –  (make Both)

Rowney Artists –  (make Both)

Maimeri Blue –  (make Both)

Utrecht –  (make Both)

The best “mixing” complement for both blues is Benzimide Orange PO62.

The best “visual” complement for blue/reddish is Cadmium Lemon PY35 and for blue/greenish is Benzimidazole PY151 or PY154.

SIDEBAR.  Don’t worry about paint manufacturers made up names, concern yourself about the “stuff in the tube” i.e., PY151, etc.  I will teach you later to understand color index codes.

Remember names on the tubes mean NOTHING.  Example one major manufacturer labels a Green called Viridian when in point of fact it is Phalo Green (very similar in looks but, one is a heavy, heavy stainer.  There are other non stainers. Only the color index code reveals their secret.

Guess what pigment costs the manufacturer the most money to buy.

Best choice if Ultramarine PB29  is the only blue you use, then Winsor and Newtons or Daniel Smith or Ultrecht will be for you.


PG18- Viridian  –  The transparent and grainy Viridian blends to create a cooler, dark green.

PB35 – Cerulean  –  The grainy opaque Cerulean blends to give an unusual and fairly neutral blue for skies and water.  Flower painters find this combination useful.  The mix is quite granular.

PR101 – Burnt Sienna  –  Gives a range of grays.  Applied densely will produce a soft gray/black.

PY35 – Cadmium Yellow  –  Gives an olive muted green.  Useful in landscapes.

PY43- Yellow Ochre  –  Produces a grayish green, which works well for landscapes.

PR108 – Cadmium Red  –  The opaque orange bias, produces a lovely burnt purple.

PV19 – Permanent Rose  –  Great mix for clean transparent purples.  Both colors lean toward each other.


  • Very Lightfast
  • Opaque to transparent
  • Semi-staining
  • Earth red to orange.

The reason why it can have a variation in color and transparency arise from manufacturers formula used.

Pigment Red (PR101)  is used to make Burnt Sienna, Venetian Red, Indian Red, English Red, Light Red, Transparent
Mars Red, Mars Brown, Mars Violet, and the list goes on.

Winsor and Newton, Rowney Artists use PR101 to make Burnt Sienna.

Let me ask you, what pigment is in your Burnt Sienna?

Are you beginning to see why names on tubes don’t matter?

It is difficult for me to list good mixes with Burnt Sienna (not knowing what Burnt Sienna you have).

But generally, it is very versatile.  It makes great grays with Ultramarine Blue, useful greens with Phalo Green PG7 or Viridian PG18.

It is really useful to tone down all colors.

If you use it rather thickly say on a wet or damp paper, it holds a good brush mark.  Example, if you paint twigs and small stems on the damp painted surface, it will not spread out; it holds its line well, with a soft look.

This is a good “what if” color.

What if mixed with……………………………….

Have a great time painting, questions gladly welcome.

God Bless  –  Jim

[Note: Subscribers to “Jim’s Watercolor Challenge” are able to view real-time video demonstrations on how to mix colors.]

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