Research on the Application of Contemporary Wireless Enamel Technique in the Teaching of Traditional Jewelry Craft Course for College Student

CURRICULUM BACKGROUND AND TEACHING STATUS

Product design (jewelry design direction) is the key professional direction of art fusion in the Gemmological Institute of China University of Geosciences(Wuhan). Its tenet is to "lead the jewelry design innovation, energize beautiful China construction and serve needs for the better life". New curriculum training mode is constantly built to enhance

the core innovation ability of jewelry art and design talents. The college pays attention to the cultivation of creative practice ability, and encourages artistic innovation supported by techniques and creativity as the source. In order to meet students' research needs of improving practical ability and expanding production skills, comprehensive jewelry craft (enamel craft) was set up as a required course in 2012. After more than ten years of reform and development, the course continues from the "cloisonne" mode to the new integration of new craft, new technology and new means represented by wireless enamel, laying a solid foundation for multiple design and creation courses.

CURRICULUM OBJECTIVES AND TEACHING METHODS

The teaching objectives of this course are divided into three aspects: the first one is about theoretical knowledge. On the basis of the traditional principle of copper wire enamel, students learn wireless enamel technology to break the inherent understanding of connotation and extension of enamel art from the aspects of excellent technology, regional differentiation and cultural difference. Secondly, it is related to the professional skills. Through systematic practice, students can learn to use new modeling methods and decorative techniques to cultivate their innovative consciousness of exploring various forms of expression in the process of craft. Third, it is involved in the technique value. To understand the importance of enamel art as the carrier of Chinese traditional culture, it should be emphasized that students should base themselves on the revival strategy of contemporary Chinese culture, with a sense of mission, and do a good job in the inheritance and innovation of enamel art.

The course is aimed at the sophomores majoring in product design (jewelry design). Before that, they had taken professional basic courses such as Introduction to Jewelry, History of Chinese Arts and Crafts, and Basic Jewelry Craft. In terms of professional knowledge, students have gained a basic understanding of the creation concept and art design principle in traditional cloisonne, Shiphoyaki and Chaktu. In terms of technical dimension, students have acquired relevant metal craft skills of filing, grinding, sawing, drawing, welding and molding. Therefore, the problems to be solved in the course are not limited to the copying of the traditional enamel techniques, but also on mastering the production essentials of the enamel techniques and the application of the new and old techniques in accordance with the design rules.

The course is arranged in an interlinked and progressive manner, with 40 hours of in-class teaching over five consecutive weeks, two days per week. This teaching method can take the applicability and coherence of the teaching content into account. According to the general learning process of the craft practice course, teacher can divides the course content into four parts. The first part is the basic knowledge of enamel craft learning. The study on the theoretical class will establish a preliminary perceptual understanding of the enamel art for the students. In the second part, the students will be organized to fire the enamel colour samples. The characteristics of enamel glaze, firing temperature and duration of enamel will be analyzed scientifically and rationally. And the regulations after the appearance will be summarized at last. The third part is the creative design practice. Students will fully understand the rich colour expression of enamel. The course will encourage students to think logically and comprehensively use the previous learned techniques to make innovations from different perspectives and expression methods in line with the creative intent. The fourth part is craft practice and work production. It emphasizes that the techniques should be learned from practice and be applied to practice. The theory is summarized from practice cases, and then further guides the design practice, and on this basis the theory is constantly tested and revised (Wan and Zhao, 2020).

COURSE ORGANIZATION AND IMPLEMENTATION

Basic Knowledge Teaching: Analysis of Theoretical Class

First of all, the course collects traditional copper tire wire enamel and wireless enamel development history on the whole, observes, analyzes and discusses the classic art case, including the crafts that predecessors combined, visual effect differences, classic works that can provide reference for the present practice, etc., so as to stimulate students' interest in learning and creative enthusiasm. For instance, Rene Lalique, famous French artist in the Art Nouveau, is represented by the work Dragonfly Women brooch (Fig. 1). After the observation of the structure and colour, it can be found that the dragonfly wings are made of planar metal veins with metal wire. Through roasting, the enamel is attached to the wings, forming an effect similar to gauze (Zou, 2009). Then the course will analyze the origin, difference and connection between wired and wireless enamel, as well as the application of wireless enamel in practical devices or decorative scenes through the linear time.

Figure  1.  Rene Lalique, Dragonfly Women brooch (Leite, 2008)

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Next is to understand the glaze, including transparent, opaque and translucent glaze use method and scope combined with the case. In this part, 94 kinds of copper enamel glaze that can be purchased in the market are classified according to the three elements of colour phase, transparency and lead content. Combined with the firing effect, 60 kinds of glaze with strong stability and clear colour are selected for the composition analysis, so as to help students clarify the composition structure and characteristics of the glaze from the source.

Finally, it discusses the complementarity of the creation theme and the craft expression methods in the context of contemporary art, emphasizes the complementarity between the strengthening of design practice and the improvement of design skills, and organizes students to collect and organize a series of decorative materials in line with the characteristics of wireless enamel technology and materials.

Preparation: Production of Enamel Glaze Standard Sample

Students are organized to fire enamel glaze samples in groups, and teachers will give on-site guidance and make comments in class. The enamel glaze is essentially a glass substance attached to the metal matrix (Tang and Li, 2004), which is the metal tire glaze colour formed by the addition of colorant, emulsion turbidity with glass as the base (Zheng, 2020). Due to the complex chemical composition and instability of enamel glaze, there is a certain span in the colour gamut range, especially the red group colour and green group colour, so beginners must burn samples as a standard colour plate before using.

In the firing process, the experimental research method is adopted. The teacher will guide the students to carry out three experiments of excessive burning, moderate burning and improper sintering of each glaze in groups. In this process, students can not only master the basic process of enamel firing, but also fully understand the colour gamut and texture difference of colour glaze in the change of high temperature and time, so as to change the previous single cognition of the colour state of enamel (Table 1). At this stage, the course should focus on cultivating students' scientific and systematic learning habits, so that they can acquire experience in glaze performance and gradually improve the design ideas, so as to help students solve the problem of future art creation theory and technology application.

Table  1.  Enamel firing experiment outcomes

Firing state	Experimental environments	Furnace temperature and duration	Experimental objects	Dimensions	The difference of colour shown in comparison to the original colour of the granular glazes	Name of glazes with no or less variance
Excessive burning	Enameling laboratory, China University of Geosciences	750 ℃, 3 to 4 minutes	60 copper blue glazes	Width: 2 cm Length: 5 cm	Large differences in colour, with graying and darkening of colours and a noticeable decrease in brightness	Dark gray, black, snow green, lily blue
Moderate burning	Enameling laboratory, China University of Geosciences	750 ℃, 1.5 to 2 minutes	60 copper blue glazes	Width: 2 cm Length: 5 cm	Reduced colour saturation	Bright green, light pine yellow, ripe orange, beige, lily blue, light gray, black
Improper sintering	Enameling laboratory, China University of Geosciences	750 ℃, 45 to 50 seconds	60 copper blue glazes	Width: 2 cm Length: 5 cm	No significant change in hue, lightness, saturation	None

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Concept Design: Innovative Thinking and Expression Mode in Design

The first is creative design during the process. The course mainly teaches students more than 10 kinds of wireless enamel techniques, including flat filling enamel, overglaze lead painting and colour painting, copper tire rust painting, kiln change in high temperature, underburned sugar cream, etched colour filling, high temperature painting, gold and silver foil, etc. Due to the difficulty of the course, students can only accurately interpret the creative theme after mastering these innovative techniques. Therefore, this link for the first time adopts the guidance method that "teachers and students discuss together, and students cogitate while doing". While communicating with the students face to face, the teachers patiently guide the students according to the uniqueness of each craft technique, and launch the non-logical thinking practice on the basis of conventional thinking. Different from the previous result-oriented thematic creation, the importance of the process is raised to the first place. And students are encouraged to regard innovation as a conscious process to improve their creative thinking ability in practice and thinking. This process does not refer to the mechanical repetition lack of connection, but to the design and creation which is to experience "the art of material and craft" and design craftsman from a large number of experiments and trials. The experience and inspiration will be flexibly applied in the theme pattern, shape and texture. For example, when making sunflower patterns, students use the fine cracks generated by the high-temperature kiln transformation process to imitate the effect of sunflower seeds, which adopts a "heterogeneous isomorphic" design method, which not only cleverly reflects the characteristics of the process but also shows the natural and vivid state of the flower tray.

The second is the form of creativity. The diversity of wireless enamel technology gives it a rich capacity for imaginative expression. Students often have different colours and pattern modes when they use the same process. If it is a composite innovation of several crafts, the effects are various. In terms of this, teachers should be good at guiding students to exert their subjective initiative to explore and accumulate new techniques and methods, be able to record the ideal effect during the firing and intended rational effect for use, including glaze name, furnace temperature and firing time, technology, etc. In this way, students will form a personalized "database" in the continuous attempt and accumulation, and then apply them to the rich diversity of the creative form and content. In addition, digital technology should also be applied, and after systematically summarizing the available "database", computer software can be used to draw renderings. The advantage of computer graphics lies in the efficiency and convenience of information storage, for example, when studying the block glaze technique, the colour filling tool can easily change the colour matching under the premise of unchanged outer contours, which is conducive to students quickly find the optimal colour combination. For an intuitive finished product, mesh forming tools can also be used to create 3D models of equal scale, which can be inspected in three-dimensional space and overcome structural scale problems that are difficult to detect in flat space. In the teaching process, the combination of practice and digital technology not only enriches the students' creative expression means, but also improves the colouring efficiency and the artistic appeal of the works.

Creative Practice: Key Points, Difficulties and Solutions of the Craft

Glaze and Correction

Dipping, spreading and brushing glaze are the three methods of glaze used in the longest filling process. Before adding glaze, you need to add water to the powder glaze to the appropriate viscosity, which is often difficult for beginners to master. The low viscosity will lead to sand and deglaze, or viscosity is too high and unable to smooth the glaze. Students should compare the glaze with the wet filling method, try to use the finger immersion test to judge the viscosity of the liquid enamel, feel the different state of the thickness of the glaze particles mixed with the water, and complete the modulation in the experiment. When glazed, if students want to fill the prepared glaze on the surface of metal objects, they should also master the correct use of the glaze shovel, such as plane, arc surface and three-dimensional turning surface of different glaze techniques. Teachers should explain it step by step depending on different situations, focusing on demonstrating the steps of quantitative immersion of glaze colour objects, and keeping the surface of glaze shovel and glaze angle consistent. In addition, on the basis of the traditional principle of Shaolan(refers to the process of filling the entire piece with a colour glaze, and then taking it to a blast furnace with a temperature about 800 ℃ to bake, and the colour glaze is melted into a liquid from a sand-like solid, finally cooled to become a gorgeous colour glaze fixed on the metal), students should be inspired to think about the mechanical structure and mutual support between enamel glaze and metal wire, and emphasize the importance of keeping the thickness of the bottom glaze and the tension balance.

The most common mistake is failing to place the metal base parallel to the supporting firing frame. The resulting angle of inclination causes the glaze to flow from high to low in the furnace. The glaze lower than the part of the parallel surface accumulates thicker and thicker to produce compressive stress, and on the contrary, the higher part produces tensile stress so that the metal bottom tire is bent or deformed under the action of the two stresses. Teachers should make plans for such problems. For example, they could follow the students to guide them, teach students some methods such as heated pressure shaping, glaze milling and edge coating, so as to make the students learn the way of improvement and remedy in the production process. The enamel basic unit items that cannot be used due to improper operation will be effectively corrected, which will greatly improve the students' error correction ability and learning efficiency.

Firing Temperature and Time Manipulation

The melting point of most of the enamel glaze used on the surface of precious metal is generally at 760-815 degrees. When firing enamel objects, the kiln temperature is usually set to the melting point temperature range of the glaze and held for 2 to 5 minutes for the glaze to be completely melted (Darty, 2015). This is a common understanding of beginners about enamel firing, but these conventional firing time can only be used as reference data rather than standard. Because the temperature and time to fire wireless enamel is affected by comprehensive factors, mainly including the difference of different processes on the surface firing state, the thickness, type and size of the metal work piece, and the softening point and dissolution point of individual glaze, etc. In addition, under the standard furnace temperature, the longer the preheating time is, the shorter the firing time will be. Conversely, the shorter the preheating time is, the longer the firing time will be. Even the temperature outside the furnace will affect the firing time. In this regard, teachers should help students understand the principle of enamel glaze melting, and judge the best time to determine the specific situation and experience, in order to reduce the probability of failure.

Compound Process

The composite innovation of multiple processes is the inevitable result of the in-depth learning of the course. Proficiency in the composite application of several wireless enamel processes can reduce errors and enhance the refinement and readability of the work. Therefore, teachers should combine the previous students' excellent works, comprehensively analyze the significance of the combination of different processes in time and space, and explain the important contents such as the sequence of composite process production, material replacement and remedial measures before the creating process (Fig. 2). For example, the firing time of the lead painting process is slightly longer than the frosting process, and the use of gold leaf under existing conditions must melt the glaze and can only be melted once, so there is a contradiction between the frosting and gold leaf process and cannot be applied at the same time, but the frosting process and the lead painting process can appear at the same time. It is also necessary to use the method of casual quiz to test students' mastery, break through technical bottlenecks, and ensure the smooth progress of artistic creation. Apart from these, in the compound process of wireless enamel, it is necessary for students to sort out the relationship between broad knowledge and specialized skill, focus on several crafts with strong learning interests for key exercises and innovative applications, so as to obtain maximum gains in limited class time.

Figure  2.  Graphic design of wireless enamel from students

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THE EVALUATION FORM OF WIRELESS ENAMEL TEACHING

The course starts with a variety of wireless enamel techniques, and encourages students to try new modeling methods, colour combinations and decorative techniques in trials, so as to cultivate their innovative consciousness of seeking novelty and change while improving their aesthetic taste. For this purpose, this course introduces a new evaluation method. Fig. 3 shows the evaluation model, which emphasizes the transition from a single point to compound one, corresponding to process experimentation, formal diversity and composite innovation, respectively. Specifically, in the early stage of the course, teachers focus on the students' mastery of the development history of enamel art by asking questions. In the middle of the course, teachers will conduct a quiz on more than 10 kinds of enamel techniques, including the mastery and proficiency of individual techniques and the comprehensive application ability of multiple techniques. At the end of the course, the evaluation for the plane decoration design and jewelry work assignment (Fig. 4), including the process quality of enamel parts, the rationalization of the connection structure, the application of composite process and ergonomic wearable design. Teachers can more accurately and objectively reflect the learning outcomes of each student through multi-faceted, multi-perspective, three-dimensional forms to avoid the disadvantages of single test.

Figure  3.  Course evaluation method

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Figure  4.  Student's final outcomes (from Kailu Ma)

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In addition, the course emphasizes the understanding of materials and craft language in the practice process, enriching and improving students' creation means. The whole process respects the development of students' personality (Shi, 2021). Teachers organize students to collect and evaluate the phased creation achievements and experimental samples. Through the exchange of identities between teachers and students, students can fully explain themselves in a free and warm atmosphere and improve their creative expression ability. In the classroom organization, teachers should also check whether each student has completed the learning objectives on time, summarize and answer common questions in time, and achieve the best effect of enamel plane decoration design and jewelry works in the mutual promotion of theory and practice.

CONCLUSION

At present, there are still a few universities offering wireless enamel courses in China, which is still a new enamel making technique. But wireless enamel works are common in international exhibitions. Based on years of teaching experience, combined with the thinking of jewelry design major in leading the development of the industry, the author summarizes a variety of wireless enamel techniques adapted to contemporary art languages, and explores the teaching mode and creation practice in the practical teaching research. This course aims to train students with the creative spirit of being pioneers, the spirit of trial and error and the craftsman spirit of striving for perfection, so as to meet the society's demand for specialization and diversification of artistic talents. It is hoped that the teaching model mentioned in this paper can provide case with study results for enamel teaching in China.