In terms of design theory, there is a consistent design rule for any design form, that is, the law of formal beauty. For the pattern design of luggage or smart backpack products, the law of formal beauty must also be followed, except that the law of formal beauty in the luggage pattern design There are unique forms of expression and techniques. The application of formal beauty design principles in pattern design is as follows.

1. Symmetry and balance
In people's daily life, we often see symmetrical forms of things, even including the human body. Such as the left-right symmetry of the human body, the symmetrical growth of plant leaves and animal wings. Usually, those symmetrical, central pattern layouts appear dignified and stable; balanced, multi-point layouts tend to be lively and relaxed. And the unbalanced and abrupt layout can create a novel and strange decorative effect.

① Symmetry: Symmetry is characterized by a relatively stable relationship between graphics, which includes absolute symmetry and relative symmetry. Generally speaking, absolute symmetry means that the shapes and colors of the components on both sides of the central axis or around the center point are exactly the same. Absolute symmetry tends to be too symmetrical and consistent, and it lacks changes, but its design style is steady and dignified, which is also the design style pursued by some luggage products.

Generally, absolute symmetry is divided into left and right symmetry, up and down symmetry, up and down left and right symmetry, reverse symmetry and rotational symmetry. The bag design shown in Figure 6-47 is a typical left-right symmetrical form, and the whole bag style is dignified and beautiful.

② Balance: In addition to symmetry in pattern design, there is also a balanced form of beauty. Generally speaking, the balance of the pattern is not restricted by the central axis and the center point, and has a symmetrical center of gravity. When designing, the composition of the plan is controlled by the center of gravity of the design.

Therefore, the use of a balanced form of pattern design, we must grasp the center of gravity, only in this way will not produce design defects of varying degrees of severity. The handbag design shown in Figure 6-48, the bow knot on the cover and the flat patch pocket at the lower right corner of the fan face through the change of pattern shape, and the roundness, length and length of the edge of the cover are matched to form a balanced design effect.

2. Repeat and contrast

①Repetition: Repetition in pattern design refers to the same and similar images, which are arranged regularly and repeatedly in a certain form. In pattern design, there are many repetitive design techniques and expressions. For example, the repetition of color is expressed in the repeated use of hue, tone, purity, and brightness of the color; the repetition of shape is expressed in the repetition of shape, composition and image; The repetition of space is expressed in the repetition of spatial location, area, volume and direction.

In addition, there are repetitions of expression skills and artistic styles, etc., which can make the works form a harmonious and unified artistic order. The bag design shown in Figure 6-49 adopts the repeated design of shapes to make the appearance of the product dignified and colorful.

The formal beauty design expression of luggage patterns

② Contrast: In pattern design, contrast is also a common design technique, and there are many aspects of contrast design performance, such as pattern contrast and color contrast. Pattern contrast usually includes pattern size contrast, light and heavy contrast, thickness contrast, density contrast, curve and straight contrast, uneven contrast, direction contrast, and convergence contrast.

As shown in Figure 6-50, the pattern design of the student backpack is to adopt a contrast technique, using pattern size, thickness and line contrast, and straight and straight to form a distinct pattern performance on the bag surface. Therefore, the use of contrast can strengthen or weaken the gap between contrasting elements and make the subject stand out.

In the pattern color contrast, there are brightness contrast, color contrast and purity contrast. The color contrast is the most abundant, and it is the strongest and most direct form of color change. The backpack design shown in Figure 6-51. Of course, in the specific pattern contrast design, if the contrast is overemphasized and the method is not used properly, it will make the pattern combination appear rigid.

3. Proportion and exaggeration
The morphological proportion is embodied in the size of the body structure and shape. The quantity, the space of the screen, etc. The change of proportion forms exaggeration, and exaggeration beautification is to strengthen the typical and representative things in the natural image to make it more characteristic and interesting. The exaggerated decorative form often breaks the original proportional relationship of the shape and structure, so that the size and proportion of the shape will change accordingly.

4. Rhythm and rhythm
Jietai refers to the phenomenon that the unit graphics regularly and continuously appear alternately in shape and color. In the luggage pattern design, the rhythm of the pattern is generally expressed by the arrangement of the elements on the surface of the package and the pattern of the luggage fabric. When designing, you can organize the strength, repetition, overlap, and stagger of the pattern image. As shown in Figure 6-52.

The formal beauty design expression of luggage patterns

5. Organization and order
Decorative patterns pursue perfect shape in layout, use space reasonably and effectively, and regularly organize and arrange graphics, which can produce an aesthetic sense of order. The layout of decorative patterns is deliberately arranged by the designer according to the law of formal beauty.

① Order: Order is a means to organize and systematize complex things. Turning the complex into simple, categorizing and consolidating are the main means to form an artistic order.

Generally speaking, the order of pattern design includes color order, shape order, space order and material order. The color order is the harmony of colors, while the shape order requires order and unity in the contrast of diverse shapes. The spatial order requires that the law of balance of physical forces be followed in the physical space, the balance of the system is emphasized in the spatial arrangement, and the principle of focal perspective is followed in the visual space. The big backpacks design shown in Figure 6-53, the pattern adopts a gradual order to produce a dynamic change effect.

The formal beauty design expression of luggage patterns

②Organization: The creation of decorative patterns regularly sorts out and summarizes the various natural objects, making them a unity of change and order. The simpler the organization, the more solemn and strict the pattern formed; the more complex the organization, the more lively and free the pattern formed. All the order of plastic art is to turn complexity into simplicity, messy into order, and blurry into vividness.