Material is the visual and tactile perception of the appearance and texture of the material. There are many kinds of luggage or best business laptop backpack materials. When painting, you should focus on expressing the visual experience of different materials. According to the design needs, choose the right tools and expression methods.

1. Fur
The fur is divided into long, short, thick and thin, soft, fluffy, and natural luster. When drawing, it is required to roughly show the characteristics of fur, instead of describing the characteristics of each type of fur completely and accurately. The main points of the performance of fur bags are as follows.

①The processing of the edge line should be arranged along the hair direction with short thin lines, interspersed densely, showing the thickness of the fur.
②The hair direction is divided into forward direction and reverse direction, and the drawing cannot be reversed. Short lines cannot be arranged in parallel, otherwise the picture will appear dull. Through the graded arrangement of different lightness group lines, the thickness and fluffy feeling of the fur are shown. The coloring sequence can be dark first, then light, first draw the color of the dark part and the boundary line of light and dark, then paint the middle gray, and pay attention to make the dark part slightly reflective, and finally paint the bright part color.
③Express the different appearances of various furs by depicting patterns and colors. For example, leopard fur is short and the pattern is irregular dot-shaped; sable fur is purple-black; yellow ferret is yellow. As shown in Figure 7-24 and Figure 7-25 big backpack.

2. Leather
Leather has the characteristics of stiff, soft, strong gloss, and good elasticity. When painting, the contrast of light and dark should be emphasized. The concave parts are painted dark and the prominent parts are painted bright. The main points of leather luggage performance are as follows.

①Leather has strong reflective performance, which can increase the contrast between highlights and shadows during performance. The convex light-receiving area should be painted brightly, the light-dark junction should be painted very dark, and the intermediate color between light and dark is less.
②The structural lines of the leather luggage are clear, and the clear lines are clear. Line drawing tools can be used to enhance this effect.
③There are various techniques for expressing leather, and tools and methods such as pencils, carbon pens, pastel methods, and friction methods can be used to express leather. As shown in Figure 7-26.

3. Woven fabric
Woven bags are made of long materials of different thicknesses such as threads, ropes, belts, strips, which are crossed vertically or diagonally in the warp and weft directions to form a bag surface, and then connect each bag surface to form a bag body. The common weaving patterns include concave and convex patterns, hollow patterns, stripes, ripples, twill, and grid patterns. When depicting, the structural characteristics of different materials and textures should be grasped for general expression.

The expression methods of woven fabrics mainly include pencil drawing method, light color method, oil pastel method and so on. As shown in Figure 7-27.

Expression methods of different materials of luggage (Ⅰ)

4. Cotton and linen fabric
Cotton and linen fabrics include thick and thin cotton cloth, cotton silk, linen cloth, canvas, etc., which are mostly used in the design and production of leisure bags or travel laptop backpacks. Due to different weaving laws, the fabric is divided into horizontal yarn, straight yarn, oblique yarn and horizontal and vertical yarn. The weave pattern of the fabric should be drawn during performance, and the embossing method can also be used. First, apply the background color with water pink, and then cover the coarse cloth on it to form a cloth pattern effect. Finally, use a deep color to outline the shadow and Wanted line. As shown in Figure 7-28.

5. Suede fabric
The surface of the suede fabric has a furry texture effect, a subtle luster, a soft and thick fabric, and a strong sense of volume. When drawing, it is not advisable to overemphasize the brush strokes. You can use the wet painting method to make the light and dark transitions soft and natural. As shown in Figure 7-29.

Expression methods of different materials of luggage (Ⅰ)