How to stretch watercolor paper

What does it mean to stretch watercolor paper? Why and how would you do it?

The main reason people stretch their watercolor paper, is because when it gets wet, as you paint, it expands creating cockles or wrinkles. These can make painting difficult for some people. By stretching your paper, the cockles are greatly reduced or removed completely. Whether or not you stretch your paper depends a lot on your skill level. Also, the type of painting you are doing may determine whether to stretch or not. Continue reading “How to stretch watercolor paper”

Removing cockles and wrinkles from watercolor paper

If you do not stretch your watercolor paper you will usually find that your paper has cockled (the creasing or wrinkling of a surface) or warped during painting to a varying degree. Then when you try to frame it your painting will not sit flat on its mat. To help with this problem I have produced a short video on removing cockles and wrinkles from watercolor paper.

I have a technique I use to fix this which will re-flatten watercolor paintings. I must say at the outset however that you do this at your own risk because if you let any water flow onto the painted surface of your watercolor painting you will ruin it!

To carry out this technique you will need the following material:

  • Flat table or bench top
  • A sheet of mat board cut into two so each half will fully cover the watercolor paintings you would like to flatten.
  • A sheet of waterproof plywood about 6mm or 1/4″ thick
  • About 7 strong clamps and or lots of heavy books
  • A trigger water spray bottle

Removing cockles and wrinkles from watercolor paper

Here is how to do it:

  • Lay one of your sheets of mat board on your table or bench top.
  • Place the paintings you want to flatten painted side down beside one another with a gap of about 2.5cm or 1″ between each.
  • With your spray bottle give the back of each painting a good spray of water, much sure no water runs under the paper where it can damage the actual painted surface.
  • I then run my hand over the back of each painting to make sure the paper is evenly wet. If need be I can add an additional spray of water.
  • I then place the second piece of mat board over the paintings and on top of that I place my plywood.
  • I then clamp all the way around my board and in the middle of the board I also place a stack of heavy books.
  • I leave all this to dry overnight.

The next day your paintings should be very flat and ready for framing.

Below you can see a short video I have produced on how to remove cockles and wrinkles from watercolor paper which you can have a look at. It should make all the above steps a little bit clearer. Hopefully this will help improve the overall presentation of your work and give your watercolors a more professional look.

Earth watercolors and color mixing

Using Earth Watercolors

The earth watercolors are already a mix of the three primary colors, however each leans a little towards one primary or secondary color. For instance, Burnt Sienna has a strong orange leaning, Raw Umber has a slight greenish tinge, Raw Sienna is a yellowish brown with a slight greenish tinge, while Yellow Ochre is obviously a Yellow with a slight red leaning.

Looking at these earth watercolors this way explains why French Ultramarine (primarily a blue) when mixed with Burnt Sienna ( Orange = Red(R) plus Yellow(Y)) gives you a beautiful dark color, almost a black at times, depending on the relative amount of each pigment mixed and the quantity of water used.

French Ultramarine + Burnt Sienna = (B + r) +(R + Y) = B+Y+R = Strong dark color.

French Ultramarine mixed with Burnt Sienna gives a strong dark color
Figure 6: French Ultramarine mixed with Burnt Sienna gives a strong dark color

French Ultramarine + Raw Umber = (B + r) +(Y + b) = B+Y+r = dull green color.

French Ultramarine mixed with Raw Umber gives a dull green color
Figure 7: French Ultramarine mixed with Raw Umber gives a dull green color

Full list of colors in my palette along with their color bias (leaning)

Here are the rest of the water colors in my Winsor and Newton palette for reference:

French Ultramarine: Warm blue =  B + r

Cobalt Blue: Almost a pure pigment not warm nor cool = B

Cerulean Blue: Cool blue = B+ y

Alizarin Crimson: Cool red =  R + b

Cadmium Red: Warm red = R + y

Cadmium Orange: Warm orange with a lot of yellow and some red = Y +  R

Cadmium Yellow Pale: Warm yellow color with a little red = Y + r

Aureolin: Cool yellow = Y + b

Cobalt Turquoise: acts like a cool greenish blue, has lot yellow in it = B + Y

Earth colors

The earth colors are more complicated as they already have some of each of the three primaries in them. Effectively they are already greys (colors made when you mix three primaries together) which lean towards one or more of the primaries. The indications after the equals sign ( = ) refer to the colors the brown leans towards.

Burnt Sienna: Orange brown earth color, can be treated as a dull orange = R + Y

Raw Umber: Slightly greenish brown earth color = b + y

Yellow Ochre: Warm Yellow earth color = Y + r

Hopefully this information about earth pigments and their component colors will help you to become more confident with your own color mixtures.

The watercolor color mixing formula

Color mixing

We can create a very simple formula from what was covered in the previous segment on color mixing, that will tell us whether we will end up with a dull (tertiary – three primary colors) or more pure color (secondary – two primary colors) from the mixture of two pigments.

If we mix French Ultramarine and Alizarin Crimson we get the following:

French Ultramarine + Alizarin Crimson = (B + r) + (R + b) = B + R = Clean mix

French Ultramarine plus Alizarin Crimson results in a bright secondary color
Figure 2: French Ultramarine plus Alizarin Crimson results in a bright secondary color

If on the other hand we mix French Ultramarine and Cad Red the result is:

French Ultramarine + Cadmium Red = (B + r) + (R + y) = B + R + y = Dull mix

French Ultramarine plus Cadmium Red results in a dull tertiary color
Figure 3: French Ultramarine plus Cadmium Red results in a dull tertiary color

It is the addition of this tiny bit of yellow in the mixture (the third primary color) which results in a more subdued purple, than the French Ultramarine and Alizarin Crimson mix. When looking at color mixtures I am leaving out any effect due to the relative transparency or opacity of the particular pigment.

Why is the color mixing formula important?

There are a number of key reasons why this is import.

Firstly, if you cannot predict just what color you will end up with when you mix two pigments together it will leave you a little uncertain and this will impact your work.

The second reason comes from the knowledge that the further away an object appears from you in a landscape then the duller the colors look due to the effect of atmosphere between you and the object you are viewing. Hence, by using this knowledge of color mixing you can easily mix duller paint combinations to correctly place your objects in the various landscape planes e.g. distant, middle distance and foreground.

Now obviously, one can learn which colors mixtures of your various pigments will produce by trial and error, but hopefully with this knowledge you will be able to take out the trial and error and much more quickly learn how to mix clean and pure or dull and grey colors at will.

It also means then you have a tool to better judge whether the addition of a new pigment to your pallet will add to the range of colors you can currently mix.

Time spent really looking at your pigments and analyzing just what their component colors are will save you a lot of confusion and frustration later on. It will also boost your confidence while painting and this will show through in your work.

By the way, pigments with the same name but from different manufacturers do not necessarily have the same component colors. For this reason the examples in this article only relate to Winsor and Newton artists quality watercolor paints. I had a student trying to mix a particular dull dark green color for which I used Raw Umber as a component it is a yellowish brown pigment with a very slight greenish tinge, but the brand of Raw Umber my student was using was more of a red brown in color so no wonder her green mixes leaned further towards the red than mine.

Here are a number of other mix formulas for your reference:

Cerulean Blue + Aureolin = (B + y) + (Y + b) = B + Y = Bright Mix

Cerulean Blue mixed with Aureolin results in a bright green color
Figure 4: Cerulean Blue mixed with Aureolin results in a bright green color

French Ultramarine + Aureolin = (B + r) + (Y + B) = B + Y + r = Dull Mix

French Ultramarine and Aureolin results in a dull green
Figure 5: French Ultramarine and Aureolin results in a dull green

In the final section we will look at the earth colors and see how the watercolor mixing formula applies to them.

Continue to: The Earth watercolors and color mixing

Watercolor techniques: wet on dry

Wet on dry watercolor painting technique

Wet on Dry is the watercolor painting technique you use when you want to place a hard or sharpe edge on your painting, though you can also use it to cover an area with a nice clean watercolor wash, see figure 6.

With the wet on dry technique the paper is dry when you lay down your watercolor wash, think of moping a floor and leaving it wet as you wash it.

The trick here is to make sure you have enough moisture on your brush that the paint mixture will freely flow out from the brush and onto your watercolor paper. It should be fluid enough that once on the paper it forms a bead of paint at the bottom edge of your brush stroke. You use this bead to continue painting down the paper to create a smooth clean looking finish.

Wet on Dry watercolor painting technique, produces hard or sharp edges
Figure 6: Wet on Dry watercolor painting technique, produces hard or sharp edges

Use the bead to help paint a smooth wash. The technique for creating a smooth wash is to keep this bead of watercolor paint flowing down the page. After you lay down your first confident brush stroke with a full loaded brush (a fully loaded brush is one that if you hold it vertically with the point facing down, the paint will drip out of it, but if you hold it horizontally it will not drip). You then reload your brush and your second brush stroke just touches the lower edge of this bead of watercolor causing it to flow down the page before creating a new bead at the bottom of this next brush stroke. It is this continuous flowing of water color down the page that leaves behind a nice smooth finish. Think of it like the sand at a beach as a wave recedes it leaves behind a smooth sandy surface.

If you have a look at my flat wash demonstration, you will see an example of this wet of dry technique.

Now if you create a watercolor wash and while it is still wet you go back into it with another color (this is often referred to as charging by some watercolor artists) then the rules of wet on wet apply.

Continue to: Dry Brush or Broken Edge Watercolor Technique