1. Line drawing effect technique
When drawing, draw a line with a pencil or a needle pen to accurately outline the shape and structure of the bag or best business laptop backpack. First draw the perspective frame of the handbag, and then describe the specific details of the shape and structure. If there are wrinkles, the image must be depicted, such as As shown in Figure 7-5. General line drawing can also vividly express the material and texture effects of luggage, as shown in Figure 7-6.

Basic method of using drawing black and white effect

2. Drawing of sketch renderings
The sketch method must have the overall observation ability to show the main characteristics of the hot topic bag. It is necessary to make sure that the pen is first and foremost, and you cannot draw a stroke at a glance, otherwise, the drawing will be either dull or trivial. Before sketching, you must coordinate the picture, and do the right thing in one go, so that the picture is full of appeal. In addition, the processing of black, white, and gray levels when sketching is also very important. Sketches are generally monochromatic, with black, white, and gray forming a contrasting relationship in the picture. Black can reach the extreme through white, and white also needs the existence of black to reflect its value. There is a broad and rich gray level between black and white. This is where the painter must focus on describing the depth. Progressive processing directly leads to the richness and depth of the picture. Whether the picture can be brilliant or not depends mainly on the gray level.

Pen, charcoal or pencil can be used for sketching. A way of expressing design intent with a pen in the form of sketches. The thickness of the line drawn by the sketch pen can be changed arbitrarily, so the object can be vivid and interesting, as shown in Figure 7-7. At the same time, the pattern, pattern and light perception of the object can also be expressed through the density of lines, as shown in Figure 7-8. Charcoal has a softer performance. The thickness and intensity of the lines can be adjusted with the intensity of the force. You can also wipe out some light and shade at will. When you use the charcoal, the picture will look very vivid.

Basic method of using drawing black and white effect   Basic method of using drawing black and white effect

3. Drawing of sketch renderings
In terms of definition, sketching is a simple depiction, which refers to a painting form that uses monochromatic lines or blocks to shape the shape, structure, texture, space, and light of an object. It is the foundation of all plastic arts. Sketch rendering is one of the quick drawing methods. It refers to the use of a single-tone black art pen such as a pencil or charcoal to describe the object. First, use the line to spread out the block surface, and then perform the black, white and gray depiction. The light-dark boundary, dark parts, bright parts, highlights, etc. of an object represent the object three-dimensionally on the paper, which is the characteristic of sketching.

The steps of sketching are to find the shape first, then trim the line, find the gray side and the dark side, and then increase the tone. When painting, you should start with the whole, first outline the shape and proportion of the object, and paint a large area of ​​light and shade. Then describe the part in detail, and finally adjust the light and shade. When drawing renderings using sketching techniques, on the premise of determining the outline and perspective of the business briefcase, use a pencil or charcoal to draw the light-dark relationship and texture of the handbag to make the object more three-dimensional and intuitive. The sketch effect is shown in Figure 7-9.

Basic method of using drawing black and white effect