Flat wash:
An area of evenly distributed color. 

Here are some examples of how flat washes are used in watercolor:
[example 1]
[example 2]
[example 3]

Paper

•  Hot press paper is more difficult to use and can end up streaky.
• Cold press is easier to use for flat washes.
• Use at least 140lb/300gsm paper to prevent pooling and buckling.
• Alternatively, you can pre-stretch your paper.

Paint

Prepare more paint than you’ll need.

Adding pigment or water to your mixture during the wash could make it streaky or uneven.

How do you know how much paint to prepare?

This is one of those instances where experience will be the best guide. Make more than you think you’ll need as a rule and experience will show you how to estimate more precisely the more you practice.

Another reason to prepare more paint than you think you’ll need is watercolor is a fast medium. Maintaining moisture on your page is a critical component to success while painting.

If you have to mix more paint in the middle of a wash, your wash might dry. Moisture is the vehicle that moves the pigment on the paper; if there is a change in moisture there will be a change in movement of the pigment resulting in an uneven wash.

Angle It

Set your paper at an angle and let gravity help.

One thing I love about watercolor is in some ways it naturally helps you paint – this happens with flat washes in particular.

Water by nature seeks balance. It automatically spreads out evenly on your page. No area will hold more water than another (as long as your paper stays flat).

By angling your paper you give water the path to distribute the paint evenly down the page. Gravity pulls the paint down and water distributes the pigment evenly on the paper. Cool, huh?!

One And Done

Aim for one brush stroke per line. Don’t’ go back into the wash and try to ‘fix’ it. Seriously, trust me on this one.

This was really hard for me in the beginning. The wash always looked like it was not quite right so I would mess with it and try to fix it and while that helped sometimes, maybe, it’s much better to just trust that the water will help it all even out. Which it does… really well.

How To Flat Wash

• Start at the top, applying paint to the full length of the top portion of your wash area.
• Leave a bead of moisture at the bottom of each stroke you paint. This bead of water helps in two ways – it helps distribute the pigment evenly and it keeps the paper damp along the edge of the wash so there is no streaking or hard lines.
• As you progress through the wash be sure to add enough paint to maintain the bead without adding so much that the bead drips down the page.
• Continue to pull the paint down the wash area by slightly overlapping the stroke before. For larger washes, it’s important to work quickly and accurately to achieve a completely flat wash.
• Use a dry brush to soak up the bead of paint remaining at the end of the wash. You can use the same brush that you performed the wash with by dabbing the moisture off on a cloth, sponge, or paper towel.

Flat Washes: The Best Place to Get Started

The beauty this technique is it’s easy to master and provides a great learning opportunity to get familiar with your tools.

• Pay attention to when and how your brush releases paint as you pull it across the length of your wash.
• Pay attention to your pigment to water ratio to understand how transparent your paints will dry depending on how much water you mixed with your pigment.
• Get to know your brushes and familiarize yourself with which brush is best for certain kinds of angles and areas.