Rolling fields of green grass, tall browned stalks of dead grass, or clusters of stubby burnt grass under a blistering sun contrast sharply from one another. Grass comes in many shapes, sizes and colours, and so should it be when you try to make a facsimile of grass in a painting. Grass is rarely the main focus of a painting, but it needs to be crafted with a subtle touch lest it become distracting. On the reverse side, if the grass is too generic or simple the landscape may appear boring and flat.
Colours and Underpaint
Mix your colours with an eye for tonal variations. Plain green grass is boring and rarely occurs in nature. For deep rolling fields look at dark hues of greens and even possibly hints of blues. Yellows and purples also work for many different types of grass. Acrylics are versatile paints, so try different thicknesses of paint as well as hues and colours. Paint the under-colour of the grass field or clumps first. This is the general overall colour of the grass. Stay away from a generic green colour and use variations. Try to capture the shape of the grass as a whole and don't worry about painting each individual blade.
Add only the defined shape of individual blades of grass where they should be able to be discerned. Place them in the foreground or any area of the painting where the eye needs to be drawn. Use a thin brush or the side of a credit card to pull the blades of the grass upward, lifting off pressure at the top of each stroke. This will give a natural tapered look to the blades. You can either apply the blades directly with your desired colour or paint over the dry undercoat with a darker colour and use the credit card to lift off the dark colour, allowing the under-paint to show through in the shape of blades of grass.
Allow the blades of grass to be placed against a contrasting colour or shade. The definable grass blades will often be in the foreground of a painting and need to stand out. Use darker hues for the grass when it stands against lighter background objects and vice versa. This contrast will give the painting a greater distinction between background and foreground objects, which in turn provides a large amount of depth to the painting.
Many beginning artists feel compelled to draw every individual blade of grass. This looks amateurish and causes serious distractions to the eye, pulling attention from the focus of the piece. Use the squint factor: Squint your eyes while looking at your painting every so often. This will help your brain break away from the small details it may be hung up on, like crafting each blade of grass in the painting, and see the work as a whole. This will give you a better sense of how well your impression of grass is working and prevent you from overcomplicating the shapes.