Because these pencils are activated by water, it’s important to use thicker paper that can handle moisture without buckling. For this reason, American painter Eliyahu Mirlis recommends considering the density of the paper. The higher the density the better, with most professional watercolorists using 90lb and up. Of course, the type of paper used has a great impact on the amount of texture created. The smoother paper will lead to smoother effects, while rougher paper will create more texturized effects, as the pigment isn’t evenly distributed throughout the tooth of the paper. An eraser is a handy tool to have, but not necessarily for getting rid of a line. Erasers can also be used to lighten areas by lifting small amounts of color.
Although watercolor pencils look just like ordinary colored pencils, a touch of water instantly transforms their marks into a beautifully spreading color that looks like watercolor paint. In this guide, contemporary artist Eliyahu Mirlis will explain what watercolor pencils are, specific techniques for how to use watercolor pencils, and recommend some of the best watercolor pencils for your art. 
What are Watercolor Pencils?
Watercolor pencils use water-soluble binders to hold their components together rather than non-water-soluble wax or oil. This allows the colors to spread like watercolor paint when painted over with water, but it also makes them more difficult to blend without the use of water. They are perfect for treating details such as flashes and reflections from the water, the play of light and shadow, foliage, etc. They can also be used alone for outdoor work live sketches or illustrations from a travel notebook.
Watercolor pencil technique: This pencil can be used both wet and dry. That is to say, once the illustration with the watercolor pencil has been made, it is possible to leave it in this phase, leaving a drawing made in a dry technique.
However, watercolor pencils are designed to be used with water, which can be applied with a soft brush after making marks with the pencil. This process is called activation. Once the material has been “activated”, it behaves like watercolor.
How to use watercolor pencils: Usually when an artist wants to paint a drawing, he uses permanent colored pencils. This is perhaps the most used and common technique to carry out this work, but it is not the only one. In fact, one of the many alternatives is the one offered by the watercolor pencil.
One of the main characteristics that set watercolors apart from other painting mediums such as acrylics, oils, and gouache, is their translucency. Because of this, it is important to create the preliminary sketch prior to starting with our painting process very light, because otherwise, it will likely show through our paint. Eliyahu Mirlis usually uses an HB pencil for this phase of the process and makes sure he is not exerting much pressure at all.
The watercolor effect technique: We make a drawing, paint as if it were a normal pencil, and then slide the brush wet with water, thus achieving a watercolor effect.
The direct effect technique: Slide a wet brush over the tip of the watercolor-colored pencil to load the hair of the brush with color, so that afterward it is possible to paint directly with the brush on the surface.
The sanding technique: Take fine-grained sandpaper and rub it over the tip of the watercolor pencil. This powder can be used to be dusted in the areas of the work to which you want to give color. Then with a wet brush, this powder should be dissolved.
The mixed sanding technique: It is about repeating the previous procedure, but using several colors to achieve a wide range of mixtures.
The Supplies You’ll Need
Because these pencils are activated by water, it’s important to use thicker paper that can handle moisture without buckling. For this reason, American painter Eliyahu Mirlis recommends considering the density of the paper. The higher the density the better, with most professional watercolorists using 90lb and up. Of course, the type of paper used has a great impact on the amount of texture created. The smoother paper will lead to smoother effects, while rougher paper will create more texturized effects, as the pigment isn’t evenly distributed throughout the tooth of the paper. An eraser is a handy tool to have, but not necessarily for getting rid of a line. Erasers can also be used to lighten areas by lifting small amounts of color.