Chapter One: Understanding Light Source to Create Three-Dimensional Form, The Joy of Botanical Drawing

Creating a detailed, three-dimensional plant drawing feels like magic to me. Perhaps this is because I tried for a long time to make my drawings look this way and failed. Something was not quite right. It might have been the perspective, the proper proportions, or a consistent use of light and shadow. I didn’t have a clear focus on how to accomplish what I wanted. I proceeded in a haphazard way, sometimes creating an area of a drawing that worked but never knowing how I achieved the success, and I was unable to do it consistently.

One of the most important concepts in botanical drawing is to understand how to use a single, specific light source to describe three-dimensional form. In this chapter, I will show you what I mean by a consistent light source and how to visualize it on forms in nature—even if you don’t actually have a light illuminating your subject this way. We will start with simple geometric shapes, practice using this idealized light source on these forms, and then immediately explore similar complex forms in nature.

To understand how light behaves on three-dimensional forms, observe the illustration [A] of an ideal light-source setup on this page. As you progress, you’ll find that the light source isn’t a mystery to solve, just a visualization exercise that will get easier and easier to do. To better understand the importance of using one light source on forms, sometimes we’ll translate a photo of our subject into gray tones. Discarding the color information can help you visualize how to create shadows, midtones, and highlights on form in the proper places. Gray tones show the placement of light and shadow without the added distraction of color.

Your goal is simple at first: make your form look three-dimensional with one consistent light source. This is your mantra. Tell yourself this over and over again, because I promise you, at first you will forget and go back to the way most of us approach drawing. We tend to think we have to draw the shadows and highlights exactly as we see them, even if we don’t have a good light source set up. But soon you will know where you want to put the highlights and shadows, even if they aren’t visible on your subject.

TERMS TO KEEP IN MIND

These are the terms I’ll explain and use throughout the book, but I’ve gathered them here so that you can reference them easily if you ever forget what one means.

BURNISHING: Blending colors for a smooth finish, usually with a light-colored pencil.

CAST SHADOW: A darker shadow area that falls on the surface on which a subject is sitting. Cast shadows are created when the form of the subject blocks the light that is hitting it. A shadow is not a form itself, so it should be extremely subtle. It should be darkest next to the edge of the shape that is casting the shadow. Shadows graduate from dark to very light and should not end in a sharp line but should fade away into the color of the paper.

CONSISTENT LIGHT SOURCE (HEAD LIGHT): Your setup or imagined light source is always placed on the left or right, in front of your subject. The light hits the subject at a 45-degree angle, and so approximately one-third of your subject is in shadow while two-thirds is illuminated.

CONTOUR LINES: An outline that follows the edges or shape of a form.

CROSS-CONTOUR SKETCH: Cross-contour lines travel across a form to help describe the three-dimensional surface and how it bends away from and toward light. These quick sketches can help you visualize the placement of light and shadow. They also often follow the venation pattern (arrangement of veins on a leaf) on a form.

HIGHLIGHT: The bright areas on the surface of a form (usually on the highest points of a three-dimensional form) created by the light source hitting it directly. Even if you don’t see highlights on your form, you can put them in to convey this important structural message in a drawing.

LOCAL OR DOMINANT COLOR: The main color of your subject.

OVERLAPPING: The spots where forms intersect each other, defining foreground and background. For example, when a leaf rolls over or curls or when one form is slightly in front of another, it creates an overlap. Rendering overlaps properly enhances space, depth, and structure.

REFLECTIVE HIGHLIGHTS: A reflective highlight is a weak light that bounces off of a surface onto a form or subject. It helps to differentiate between two overlapping forms or separates a form from a cast shadow. The reflective highlight should not be as light in value as a highlight. It should be very subtle, at a value of 4 or 5 (see “Create a Nine-Value Tone Bar” on this page). It’s best when it feels like glowing light and is not just a straight, empty line.

PICTURE PLANE: For our purposes, think of the picture plane as an imaginary perpendicular window right up against your subject. Taking measurements on this plane helps you to measure in perspective.

THUMBNAIL SKETCH: This simple, quick, small shape drawing of your subject is a reminder of how the light illuminates your subject so that you know where to put the shadow side, the midtones, and the highlight.

TONE OR VALUE: These terms refer to how light or dark a color appears.

Practice visualizing light on form (use your head light) to help you make decisions on how to draw your form, even when you aren’t seeing a single light source. It is also important to understand that even if you don’t actually see the highlight and shadows, you can still put them on the form in your drawing. It takes a while to get used to this concept, so it’s best to practice and remind yourself of it. Remember your mantra: make your form look three-dimensional with one consistent light source.

Look at my two examples of citrus drawings (following). The tangelo shows light coming from the upper right, while the Meyer lemon shows light coming from the left. The effect is the same but just from opposite sides. If possible, turn off all other light sources in the room and close window shades so that your subject is receiving light from only your light-source setup. The box can help block out other light sources. Note: If you are right-handed, I recommend placing this light on the upper left. If you are left-handed, place this light on the upper right. The goal is to have a good source of light on your subject that doesn’t cast a shadow on your paper from your drawing hand as you are drawing.

Position your box on a table and place the lamp in front of the box on the left side. (A simple gooseneck lamp is fine, though you can also use a specific light that is closer to daylight, such as an OttLite. On the fly, I light my subject with a flashlight or my cell phone light to help get an overview of the highlight, the midtones, the shadows, and the cast shadows.) The light should be hitting your subject at about a 45-degree angle from the upper left or right. This position is your consistent light source.

Several small plant specimens in various shapes (try a small tomato, branch, leaf, and flower)

• Practice paper (anything you have available, doesn’t need to be good paper)

There are several ways to use watercolor pencils, but this is my favorite. When you draw on a plastic palette made for watercolor pencils, or a substrate plastic, such as Grafix Dura-Lar Film or Yupo synthetic paper, the surfaces have enough friction to lay down the watercolor pencil, so when water is added to the pigment, it turns into paint. You can mix your watercolors to make other colors and also apply the watercolors directly to your drawings from the paint you mix on the palette. The palettes can also be washed and reused over and over again.

Slow-Toning to Create a Seamless Blend of Values from Light to Dark Using Watercolor and Colored Pencil

In this lesson I introduce the mechanics of creating tonal variation with a slow buildup of layers. Please focus on these two concepts as you practice the step-by-step techniques. I’ll create tonal variation with a slow buildup of layers starting with a watercolor tone bar and then colored pencils, which change gradually from the lightest tone (the white color of your paper) to the darkest tone (as dark as you can get with your darkest pencil). This is the key to making forms look extremely three-dimensional. It works best to understand this concept by first working only in neutral tones without the distraction of colors.

Note: You can practice all lessons without using watercolor, but this requires more layering of colored pencils and more burnishing. It’s a slower technique but allows for more control for the beginner. The watercolor speeds up the process. With these techniques, combined with the understanding of a consistent light source that you’ve just acquired from the first lesson, you’ll start to gain confidence. At the same time, you’ll feel relaxed (because repetitive, slow drawing feels good), and soon a feeling of well-being will come over you. These exercises are really fun to do when you take the time to do them slowly and methodically, and you’ll find that they become an important component for all your drawing. Soon your confidence level will rise, and you will no longer be telling yourself that you have no talent and cannot draw!

I like to let my watercolor dry completely before drawing on top of it. How long is this? It depends on your climate and how wet you got your paper. I would say it’s a good idea to wait twenty minutes for your paper to dry, but waiting even longer is always better. I often work on more than one drawing or area at a time so that while one area of watercolor is drying, I can work on something else. If you try to draw on top of your watercolor while it is not completely dry, the paper will not take the pencil and sometimes the pencil can start to chew up the paper.

This tone bar will be used as your guide for a complete range of values from shadow to highlight. You can use this guide to help you evaluate your drawings and make sure you have created a complete range of values on each subject.

To create smooth, seamless toning in your tone bar, start on the right side with slow toning, then with each layer, cover a little bit less of the tone bar, leaving the left side of the tone bar lightest. Switch the directions of your strokes, and even consider turning your paper to continue laying down tone in a relaxed, comfortable manner. This is very important. You want this process to be a very slow buildup of values, and for each layer, apply smaller and smaller strokes. The final layers of strokes become tiny circular strokes that fill in the light areas of fine texture on the paper, creating a seamless, blended tone bar. If you are feeling a sense of calm and well-being, chances are you are applying your tone correctly.

You will use this technique, or develop your own variations of this technique, throughout the book. It is most important to find your own method of achieving the goal of creating many layers of seamless tonal variation. Notice the feeling of space, depth, and movement from dark to light even in a simple tone bar such as this. In the end, you should feel relaxed and proud of your tone bar. If you work too quickly and don’t have a nice, smooth transition with all nine values, try another tone bar. It is fun to allow yourself the luxury of creating slow, seamless tonal drawings. And not only is it fun, but it is an essential skill to develop. Once mastered, you will be on your way to creating realistic three-dimensional drawings. Who knows, this could become your daily meditation!

A curved tone bar represents a form that is curved or bending away from or toward light, thus creating various values. Use the same technique for building layers from the previous lesson on a curved tone bar here. This time you’ll leave the blank area inside the bar, near the left edge. This lightest area is an imagined highlight. As you build tones to create a bending tone bar, you will start to see the three-dimensional illusion develop right before your eyes. This is a magical feeling, so be sure to go slowly and enjoy the process. I often imagine that my pencil point is a tiny insect crawling across this curved bar, starting in a dark, shadowed valley and slowly creeping up toward the sunlight at the top of a hill as I get to the highlight.