Whether you are painting from life or from a photograph, you'll want to consider the type of grass you intend to paint. Is the grass wheatlike or beige in color? Or is it deep green, yellow or mint? Is the grass part of a perfectly manicured suburban lawn or is it in a field growing tall and full of wildflowers? Different techniques will be employed based on your answers to these questions.
In almost all cases, the color of the grass will be a mixture of light and dark hues. Select colors that convey the depth of the grass. For example, if you are painting a field of wheat, choose varying shades of beige from rich, almost yellow shades to light, practically white tones. The darker colors are utilized to paint the grass that is farthest away (i.e., the background), while the lighter shades are utilized in the foreground.
The texture of grass can vary from short clumps around a tree or plant to tall blades swaying in the wind. The type of brush you use is critical in creating the right texture for your grass. Short clumps of grass will require wide, thick brushes, whereas tall, thin grass warrants use of a thinner and perhaps longer brush. The brush stroke will also play a role in painting realistic grass. Dotted or stabbed brush strokes create a thick, clusterlike effect and long fluid brush strokes contribute to tall, fieldlike blades of grass. In addition, layering of acrylic paint is a good way to add texture: adding more layers will create a thicker, denser quality.
Another approach to painting grass is to scratch out the various blades using the end of a paintbrush or the corner of a credit card. Add paint to the canvas or surface area and etch in the grass using whatever tool you choose. Lastly, paint over the etched grass with a light color or clear glaze.