Hand-drawn oil painting sketches are an important initial stage in oil painting creation, laying the foundation for the subsequent formal drawing. The following is an introduction from several aspects, including preparatory work, composition techniques, modeling and line techniques, and color estimation techniques:
Preparatory work
Tool selection: Choose the appropriate drawing tool based on personal habits and the requirements of the picture. Pencils are commonly used sketching tools. Pencils of different hardness can draw lines of different depths and thicknesses. For instance, the H series pencils are relatively hard and are suitable for drawing fine lines and details. The B series pencils are relatively soft and easy to color, making them suitable for expressing light and shade contrasts. Charcoal can quickly draw thick lines, creating a strong visual effect, and is suitable for quickly capturing inspiration and expressing general Outlines. In addition, colored chalk can be used for simple color estimation and application, providing a reference for subsequent oil painting colors.
Preparation of drawing paper: Choose drawing paper of moderate texture with a slightly rough surface. Such paper can not only adhere well to the lines of pencils or charcoal but also be convenient for subsequent modifications. If the surface of the drawing paper is too smooth, the lines are prone to slipping and are difficult to control. If it is too rough, it may affect the fluency of the lines. Before drawing, you can fix the drawing paper on the drawing board with tape to prevent it from moving during the drawing process.
Composition techniques
Determine the theme and the proportion of the picture: Before starting to draw a sketch, it is necessary to clarify the theme of the painting and the content you want to express, and then determine the proportion of the picture based on the theme, such as common rectangles, squares, etc. Different proportions can bring people different visual feelings. For instance, rectangular images have a sense of stability and extension, making them suitable for depicting landscapes, people and other subjects. A square picture is more balanced and concentrated, making it suitable for depicting still life or emphasizing a certain subject.
Apply composition rules: Master some basic composition rules, such as the rule of thirds, symmetrical composition, and triangular composition, etc. The rule of thirds divides the picture into a nine-square grid, placing important elements at the dividing lines or intersections to make the picture more balanced and attractive. Symmetrical composition can create a sense of solemnity and stability, and is often used to depict architecture, portraits of people, etc. The triangular composition has stability and an upward dynamic, which can make the picture more vivid.
Arrange the positions and densities of elements: Reasonably arrange the positions of each element in the picture and pay attention to the density relationship between elements. Avoid overly uniform or crowded distribution of elements. There should be a distinction between primary and secondary elements and a sense of rhythm. For instance, in landscape paintings, elements such as distant mountains, nearby trees and figures in the middle can be reasonably arranged to make the picture have both a sense of layering and a sense of wholeness.
Modeling and line techniques
Observation and Generalization: When sketching, one should learn to observe the basic shapes and structures of objects and summarize them into simple geometric shapes, such as circles, squares, triangles, etc. In this way, the features of the object can be quickly captured, facilitating subsequent in-depth depiction. For instance, when drawing a figure, one can generalize the head as a circle, the body as a rectangle, and the limbs as a cylinder, etc.
Line expression: Use different lines to represent the texture, light and shadow, and spatial sense of objects. Thick lines can express the weightiness and the sense of closeness of an object, while thin lines can convey the delicacy and the sense of distance of an object. Solid lines can clearly outline the contours of objects, while dashed lines can express the blurriness and spatial sense of objects. When drawing light and shade, it can be expressed through the density of lines. The denser the lines, the darker the color. The sparser the lines, the lighter the color.
Motion capture: If there are dynamic elements in the picture, such as people or animals, pay attention to capturing their dynamic features. The movement trajectory and key postures of the object can be quickly recorded with simple lines by observing them. For instance, when drawing a running figure, one can capture the leg movements and the Angle at which the body tilts to convey the dynamic sense of running.
Color estimation techniques
Determine the main color tone: During the sketching stage, the main color tone of the picture can be roughly determined, that is, the dominant color in the picture. The choice of the main color tone should be in line with the theme and atmosphere of the painting. For instance, warm tones can create a warm and lively atmosphere, while cool tones can create a calm and mysterious one.
Color matching: Consider the matching relationship between different colors and apply the principles of color contrast and harmony. Contrasting colors can enhance the visual impact of a picture, such as red and green, yellow and purple, etc. Harmonious colors can make the picture more harmonious and unified, such as the combination of adjacent colors or colors within the same color family. On the sketch, you can use simple color blocks or colored chalk to create a preliminary sense of the effect of the colors.
Light and shadow color: Estimate the influence of light and shadow on color. The color of objects will change under different lighting conditions. For instance, under the sunlight, the colors of objects will be more vivid and bright. In the shadow, the color of objects tends to be darker and cooler. In the sketch, different shades of color or lines can be used to represent the changes of light and shadow, providing a reference for the subsequent coloring of the oil painting.