The Use of Ink in Visual Arts

Introduction

The philosophical framework for considering ink in visual arts has deep roots in Eastern aesthetics, where the material and the creative process are inseparably linked to worldview. In Chinese painting, for example, ink is not merely a pigment but a medium through which the artist expresses their inner state and philosophical understanding of the world. The concept of Xie Yi (寫意), or "painting of ideas," emphasizes that a work of art should convey not so much the external likeness but the spirit and essence of the object, achieved through laconic yet expressive ink strokes [Wu, 2015]. This tradition, as Richard Wu notes, is a kind of "cultural therapy" allowing the artist and viewer to engage in an "evocative spatial dialogue" with the artwork, where metaphor and analogy play a key role [Wu, 2015]. Ink becomes a tool for exploring not only the visible but also the invisible, inner world.

At the same time, the Western tradition, although primarily using ink in graphics and preparatory drawings, also recognized its unique qualities. The monochromatic nature of ink, its ability to create deep contrasts and subtle tonal transitions, allowed artists to focus on form, composition, and line, eliminating the distracting factor of color. This resonates with Rudolf Arnheim's ideas that visual perception is not a passive reflection of reality but an active structuring process where line and form play a fundamental role [Арнхейм]. In this context, ink serves as an ideal tool for studying and conveying these basic visual elements, enabling the artist to explore the "blackest black" and its interaction with white space, which, according to Jared Yates Sexton, allows "rethinking difference" [Sexton, 2021].

So why have artists chosen ink for centuries? This question goes beyond a simple choice of material. It touches on deep aspects of artistic expression, cultural traditions, and philosophical approaches to art. We will examine how the unique physical properties of ink, its historical role in various cultures, and the diversity of techniques allow artists to achieve special expressiveness, creating works that continue to inspire in the modern world.

Detailed Exposition

The Role and Significance of Traditional Chinese Calligraphy in the Modern World

What is the role of the ancient art of calligraphy in a world increasingly immersed in digital technologies and striving for instant information consumption? This question becomes especially acute when it comes to traditional Chinese calligraphy, an art deeply rooted in philosophy and culture. On one hand, there are efforts to preserve it as cultural heritage and even use it therapeutically; on the other, there is a desire to apply modern technologies for its study and preservation.

Traditional Chinese calligraphy is essentially the soul of Chinese culture, reflecting the wisdom of generations [Jian et al., 2019]. It is not just a set of symbols but a complex system where every stroke and line carries deep meaning. Its preservation, like any craft, becomes a task passed down from generation to generation. But how exactly should it be preserved, and how can it remain relevant today?

Richard Wu proposes viewing calligraphy, particularly Xie Yi painting, as a form of cultural therapy [Wu, 2015]. He describes Xie Yi as a practice involving concepts of "evocative spatial dialogue," metaphor, analogical representation, rhythm, play, integration, and images of the authentic self. It is not merely drawing but a profound process of self-knowledge and healing. Wu draws parallels between these elements and the functions of modern analytic psychotherapy, suggesting that calligraphy can serve as a bridge between ancient wisdom and contemporary psychological needs [Wu, 2015].

Wu further develops this idea, asserting that engagement with Chinese ink painting and psychotherapy is a "healing of multigenerational displacement" experienced by many in the Chinese diaspora [Wu, 2021]. He sees cultural practices as a way to maintain connection with roots, which is especially important amid rapid urbanization and Westernization that China has undergone since the early 1980s [Wu, 2016]. Calligraphy thus functions not only as an aesthetic practice but also as a tool for cultural and personal restoration.

Beyond therapeutic and cultural significance, calligraphy also attracts technological interest. Researchers such as Jian and colleagues actively study possibilities for three-dimensional reconstruction and evaluation of traditional Chinese calligraphic art [Jian et al., 2019]. Their work aims to "study traditional Chinese calligraphy art through 3D reconstruction and assessment," enabling not only preservation but also analysis using modern methods. This opens new horizons for understanding the subtleties of strokes, brush pressure, and spatial composition previously accessible only to experienced masters.

Such technological approaches do not merely archive works but provide opportunities for deeper study of their structure and dynamics. For example, 3D models allow analysis of stroke height and depth, which is critical for understanding the unique texture and expression inherent in Chinese calligraphy [Jian et al., 2019]. This can be especially useful for teaching, allowing students not only to see but also to "feel" the master's work.

At the same time, it is important to note that aesthetic preferences in Chinese ink painting can be quite universal. Wu and colleagues' research showed that gender differences do not significantly affect preferences for most attributes of Chinese freehand painting among elderly Chinese [Wu, 2021]. Characteristics such as "color should not be too bright," "relaxed, simple, and flexible writing style," and "natural landscapes" demonstrate a shared appreciation among both men and women. This speaks to deeply rooted cultural values transcending demographic differences.

Sophie McIntyre, in her study "Ink Remix: Contemporary Art from Mainland China, Taiwan, and Hong Kong," shows how contemporary artists reinterpret traditional ink, integrating it into new media including photography, video, animation, and computer art [McIntyre, 2015]. This demonstrates that calligraphy is not frozen in time but continues to evolve, adapting to new forms of expression. It becomes not just an object of preservation but a source of inspiration for innovation. Traditional Chinese calligraphy in the modern world balances preserving its authenticity as a cultural and therapeutic tool and adapting to new technological possibilities. It remains a living art that connects us with the past and offers new paths for self-expression and understanding in the present. The open question is how these diverse approaches—from therapeutic to technological—can be integrated to create a fuller and more multifaceted understanding of this unique art, which leads us to the need to develop methods for analysis and classification of Chinese ink painting.

Methods of Analysis and Classification of Chinese Ink Painting

In the previous section, we discussed how Chinese calligraphy and ink painting remain relevant in the modern world, serving not only as traditional art but also as inspiration for new forms. However, to truly appreciate and understand this art, it is necessary to delve into its internal structure, how it is created, and how it can be analyzed. Chinese ink painting is not just an image; it is a complex system where every stroke and line carries deep meaning and reflects the artist's skill.

Traditional Chinese calligraphy, or shu fa ("the way of writing"), is deeply rooted in the aesthetic tradition of Chinese culture [Peveto, 2020]. It is an art encompassing the country's entire history and culture, and understanding it gives us a key to China's past and present. But how can we objectively analyze what seems so subjective and ephemeral? How to distinguish a master's work from imitation when it comes to nuances of brush movement and ink distribution?

One of the most promising approaches to analyzing Chinese ink painting is the use of three-dimensional reconstruction. Researchers Muwei Jian, Junyu Dong, and colleagues emphasize that to truly understand the "powerful meaning and beauty of Chinese calligraphy art," it is necessary to capture the detailed view of the 3D geometry of the calligraphy surface. They developed a 3D reconstruction method based on photometric stereo, which allows capturing the tiniest features of strokes, their relief, and interaction with paper.

Why is this so important? Because traditional Chinese ink painting, unlike many Western techniques, does not merely apply pigment to a surface. It creates microrelief where the thickness of the ink layer, its absorption into paper fibers, brush speed, and pressure form a unique texture. These nuances, invisible to the naked eye on a flat image, are key to assessing authenticity and mastery. Jian, Dong, and their team note that their method "reflects the intrinsic characteristics of the 3D geometry of the Chinese calligraphy surface more effectively than other modern methods" [Jian et al., 2019].

Their approach is not limited to reconstruction. It also includes an evaluation system comparing 3D calligraphy shapes from a reference collection with the user's handwriting. This allows not only analysis but also teaching, providing feedback on stroke quality. For example, they use the Iterative Closest Point (ICP) algorithm for aligning 3D shapes, enabling quantitative assessment of parameters such as line accuracy and smoothness [Jian et al., 2019]. This opens new horizons for studying and preserving this art, allowing even robots to reproduce Chinese calligraphy, as shown by research by Zhe Ma and Jianbo Su [Ma, Su, 2017].

However, besides 3D reconstruction, other analysis methods exist. Some researchers focus on stroke analysis and stochastic models. Li and Wang [Li, Wang, 2004] argue that "for certain types of paintings, only strokes provide reliable information to distinguish artists." Chinese ink painting is a vivid example, as it lacks colors and even clear tonal transitions, with all expressive richness concentrated in stroke dynamics and form. The two-dimensional Hidden Markov Model (2-D MHMM) they use analyzes relatively large image areas, capturing properties of painterly strokes.

This approach is complemented by work from Sun, Zhang, Zhen, Wang, and Jing [Sun et al., 2015], who also explore stroke-based methods. They attempt to identify unique "handwritings" of artists by analyzing parameters such as line thickness, speed, brush pressure, and ink distribution. Each artist has a unique style manifested in the smallest details of their strokes, much like a person's handwriting.

At the same time, it is important to understand that these methods cannot always fully capture the complexity and multifaceted nature of Chinese ink painting. For example, Zhang, Gibson, and others [Zhang et al., 2015] develop fast 3D reconstruction systems using inexpensive cameras, making the technology more accessible. However, despite technical progress, the question remains: can algorithms capture qi—the vital energy considered by many to be the essence of Chinese painting?

Research in computer vision and machine learning, such as work by Mengdi Wang and colleagues [Wang et al., 2016] on evaluating Chinese calligraphy using DBSC vectorization and ICP algorithm, shows that certain aesthetic parameters can be quantitatively measured. However, as Ariane Peveto notes [Peveto, 2020], Chinese calligraphy is not just a set of strokes but "an art deeply rooted in a long tradition of aesthetic beauty." Can a machine ever truly appreciate this beauty?

Some researchers, like Xu, Jiang, Lau, and Pan [Xu et al., 2012], attempt computational evaluation and reproduction of Chinese calligraphy's beauty, bringing us closer to understanding its aesthetic principles. However, as Michael Sullivan [Sullivan, 1998] emphasizes in his review "Three Thousand Years of Chinese Painting," this art has deep historical and cultural roots that do not always lend themselves to purely technical analysis.

Methods of analysis and classification of Chinese ink painting develop along two main directions: on one hand, detailed 3D reconstruction capturing physical stroke characteristics; on the other, algorithmic analysis of 2D images focusing on patterns and styles. Both approaches strive for objective evaluation but face the challenge of measuring the elusive aesthetics integral to this art. This question becomes especially acute when moving to other cultures where ink is used differently, such as Arabic calligraphy, where form and line acquire different symbolic and aesthetic meanings.

The Use of Ink in Arabic Calligraphy

In the previous section, we examined methods of analysis and classification of Chinese ink painting, delving into stylistic features and technological aspects such as 3D stroke reconstruction [Jian et al., 2019]. However, ink as an artistic material is not limited to East Asian tradition. Its unique properties—color depth, ability for subtle gradations, and line expressiveness—have found application in entirely different cultural contexts, notably Arabic calligraphy. This shifts us from the world of landscapes and characters to the realm of sacred writing, where ink becomes a tool for embodying the divine word.

Islamic art, unlike many other traditions dominated by figurative imagery, developed around language and writing. Arabic calligraphy, emerging with the Quran, became one of the most outstanding forms of visual art in the Islamic world [Alashari et al., 2019]. Here, ink is not merely a means of creating images but a carrier of meaning, an embodiment of sacred text. While Chinese calligraphy values expression and individuality of strokes, Arabic calligraphy emphasizes strictness, harmony, and mathematical precision of forms, though allowing artistic interpretation.

The transition from Chinese ink painting to Arabic calligraphy demonstrates the remarkable adaptability of the material. In China, ink conveyed nature's dynamics, created atmospheric landscapes, and expressed the artist's inner state through free, sometimes unpredictable strokes [Hu, 2023]. In the Arabic tradition, ink serves to construct complex geometric letter patterns, each element having a strictly defined place and proportion. This does not imply absence of expression but manifests differently—through rhythm, balance, and virtuosity rather than spontaneity.

Arabic calligraphy features various writing styles, each with its canons and aesthetic principles. For example, Kufic style is angular and monumental, while Naskh and Thuluth are more rounded and flowing. In each style, ink plays a key role, allowing the calligrapher to achieve the necessary line thickness, smoothness or sharpness, and create contrast between black script and white background. This requires not only artistic sensitivity but deep knowledge of Arabic letter anatomy.

Interestingly, even within the strict regulation of Arabic calligraphy, ink allows the artist to express individuality. Choice of ink type, dilution, and characteristics of the qalam (reed pen) or brush affect the final result. The calligrapher can vary black density, creating more or less saturated areas, adding depth and volume. This is reminiscent of Chinese ink painting masters using different ink dilutions to create effects of mist or mountain haze [Wang et al., 2018].

Comparison with Chinese calligraphy, where, as noted by Muwei Jian et al., even with 3D reconstruction for handwriting evaluation, cursive style remains difficult to analyze due to its freedom and irregularity, highlights differences in approaches. In Arabic calligraphy, although degrees of freedom exist, basic letter structures remain unchanged. This allows creating evaluation systems based on stricter parameters than in the case of "unrestrained" cursive.

Ink in Arabic calligraphy is not just pigment but part of a cultural code passed down through generations. Calligraphy masters spend years honing their skills, studying letter proportions and forms to produce exemplary works. This learning and knowledge transmission process closely resembles traditional Chinese calligraphy training, where continuity and deep understanding of classical models are also important [Jian et al., 2019].

However, despite deep cultural roots and traditional methods, modern technologies are beginning to penetrate this field as well. While 3D reconstruction methods for analysis and evaluation exist in Chinese calligraphy [Jian et al., 2019], attempts at digitization and modeling also appear in Arabic calligraphy. This opens new prospects for preservation and study of this art, as well as for creating interactive systems to help students master complex writing techniques.

Ink, as a universal material, demonstrates its versatility, moving from the expressive freedom of Chinese ink painting to the strict yet deeply aesthetic form of Arabic calligraphy. This underscores that material properties can be adapted to entirely different artistic and cultural tasks while retaining expressiveness. The open question remains how these traditional techniques, deeply rooted in manual labor and tactile sensation, will interact with new digital approaches to rendering and imitation, which we will discuss next.

Modern Approaches to Rendering and Imitation of Ink Painting

If in Arabic calligraphy ink serves as a tool for embodying sacred texts and aesthetic expression, in the context of digital technologies its role undergoes radical changes. We move from physical interaction with the material to its imitation, from manual skill to algorithmic generation. This raises the question: can we even speak of "ink art" when ink itself becomes just a set of pixels or a mathematical model?

Modern approaches to rendering and imitation of ink painting divide into two main directions. The first is rendering based on physical stroke models, aiming to reproduce real properties of ink and paper. The second is style generation and transfer using neural networks, focusing on training algorithms to recognize and reproduce artistic styles. Each direction offers its perspective on how digital technologies can interact with traditional art.

Stroke- and physics-based rendering attempts to capture the essence of ink's interaction with the surface. Researchers such as Xu, Yang, and Wu [Xu et al., 2012] propose a real-time rendering approach that imitates the style of Chinese ink painting on geometric models. They create an "ink trail" as particles, then extract classified strokes from 3D models using existing geometric information, and finally combine strokes and ink to create a "captivating painted image." Here we see an attempt to decompose the drawing process into basic elements synthesized in a digital environment. This is not mere copying of appearance but modeling the physics of the process.

Such physics-based methods strive to reproduce not only visual effects but also stroke dynamics, texture, and surface interaction. Wang, Shen, and Ding [Wang et al., 2018], as well as Wang, Li, and Zhu [Wang et al., 2018], contributed to this direction by developing algorithms considering parameters like paper absorbency, ink spreading, and brush pressure. This allows creating images that not only look like ink paintings but possess their characteristic, elusive qualities such as tonal gradations and "dry brush" effects. However, how deeply can one penetrate this physics without losing artistic intuition?

Another approach, proposed by Jian and colleagues [Jian et al., 2019], focuses on 3D reconstruction and evaluation of traditional Chinese calligraphy. They use photometric stereo to create 3D models of calligraphic works, enabling analysis not only of flat images but also stroke relief. This opens new possibilities for style study, as "with 3D geometry display of calligraphy surfaces, people can more effectively study and explore Chinese calligraphy style" [Jian et al., 2019]. Their method eliminates distortions caused by uneven lighting, critical for accurate reconstruction.

Jian et al. [Jian et al., 2019] detail the mathematical apparatus for reconstructing 3D surfaces using multiple images taken under different lighting. They show how image intensity $I(x, y)$ can be decomposed into lighting components $L(x, y)$ and surface reflectance $R(x, y)$ [Jian et al., 2019]. This allows separating stroke properties from external shooting conditions, a fundamental step toward understanding and imitating its true form. The question remains whether a mathematical model can fully capture the expression born from the unpredictability of a live stroke.

Alongside physical modeling, a direction using neural networks for style generation and transfer develops. Gan and Wang [Gan et al., 2021], Wu, Yang, and Xu [Wu et al., 2020], and Sun, Wu, Li, and Meng [Sun et al., 2022] explore how algorithms can "learn" style and apply it to new data. For example, Wu, Yang, and Xu [Wu et al., 2020], in their work CalliGAN, propose a Chinese calligraphy character generator considering both style and structure. They note that "Chinese characters are rich in forms and details," and their method "generates high-quality Chinese calligraphy characters" [Wu et al., 2020]. Here we see neural networks attempting to imitate human ability to visualize and mimic handwriting, separating calligraphic style and textual content.

These style transfer methods essentially learn from vast datasets, identifying patterns and features defining particular artistic handwriting. Sun and colleagues [Sun et al., 2015] proposed a method for classifying Chinese ink painting authorship based on strokes using hybrid convolutional neural networks. This shows that even subtle nuances like individual stroke style can be analyzed and categorized by algorithms. However, if an algorithm can classify, can it truly create?

The problem is that neural networks, while capable of impressive imitation, often operate as a "black box." We see the result but do not always understand how it was achieved. This differs from physical modeling, where each parameter has a specific meaning and influence. Lothar Ledderose [Ledderose, 2000], in his work on mass production in Chinese art, shows how standardized parts and modules were used to create complex works. Perhaps neural networks essentially do the same but at a more abstract level, creating "style modules" that are then combined.

Nevertheless, even with the most advanced algorithms, the question of authenticity arises. Can imitation, no matter how perfect, replace an original work created by a master's hand? Jared Yates Sexton [Sexton, 2021], in his essay "Basic Black," reflects on the search for the "blackest black"—an absolutely absorbing, non-reflective surface. He sees this as not only a scientific but also an artistic problem, where black becomes a space in which other colors find themselves. In the context of digital ink imitation, we also seek a kind of "perfect black," but already in virtual space.

Ultimately, modern approaches to rendering and imitation of ink painting do not merely copy but reinterpret traditional art. They allow us to view it from a new angle, analyze its structure, dynamics, and even philosophy through the lens of algorithms and mathematical models. However, despite all technological advances, the question remains: what do we lose when translating a living, breathing ink stroke into data and pixels? And how does this affect our understanding of art, which has always been deeply connected to human touch and the uniqueness of the moment?

Philosophical and Cultural Aspects of Chinese Ink Painting

In the previous section, we discussed how modern technologies strive to imitate and reproduce ink painting, achieving remarkable accuracy in conveying visual characteristics. However, when it comes to Chinese ink painting, mere reproduction of form overlooks its profound essence. This art is inseparably linked with Chinese philosophy and cultural traditions, making it not just a technique but a worldview expressed through strokes and lines. How can one imitate what is not only an image but also a reflection of spirit?

Chinese ink painting, or guohua, is more than a set of pictorial techniques. It embodies Chinese philosophy, particularly Daoism, Confucianism, and Buddhism [Hu, 2023]. It reflects ideas of harmony with nature, cyclicality of existence, and striving for inner perfection. The artist working with ink does not merely copy reality but filters it through themselves, conveying their understanding of the world. It is not so much an image of the object as its essence, its breath.

For example, in Chinese calligraphy, an integral part of ink painting, every brush stroke carries not only aesthetic but symbolic meaning. As Jian and coauthors note, "traditional Chinese calligraphy art, reflecting grassroots wisdom, is the soul of Chinese culture" [Jian et al., 2019]. They emphasize that calligraphy is not just writing but "the art of writing," where "handwriting reveals the essence of personality and character" [Jian et al., 2019]. This means that even in the creative process, there is a deep connection between the artist and their creation, between their inner world and external expression.

Unlike the Western tradition, which often emphasizes realism and detail, Chinese ink painting seeks to express the spirit of the subject rather than its literal appearance. The empty space on the scroll, the so-called "void," plays as important a role as the depicted elements. It symbolizes infinity, the unspoken, potential. It is not merely a background but an active compositional component interacting with the image, creating a sense of depth and atmosphere.

The philosophical concept of qi (life energy) permeates all Chinese art, and ink painting is no exception. Brush movement, pressure, speed—all must convey the qi of the object, its inner dynamics. The artist must be able to "feel" the qi of bamboo, mountain, or water to then transfer this sensation onto paper. This requires not only skill but deep meditative practice and unity with nature. Peveto notes that "values and ideology of traditional Chinese philosophical worldview are traced in ink painting" [Peveto, 2020].

However, despite this profound philosophical foundation, the modern world faces challenges questioning traditional approaches. For example, Jian et al. [Jian et al., 2019] describe a 3D reconstruction and evaluation system for Chinese calligraphy. The system aims to help learners "study, appreciate, evaluate, and improve their Chinese calligraphy writing skills independently" [Jian et al., 2019]. This is undoubtedly a useful educational tool, but can it convey the very "beauty of strength" or the "richness of the calligrapher's personality" manifested in brush movement?

The authors claim their model "works with a 3D surface height map to utilize intrinsic characteristics of the Chinese calligraphy surface" [Jian et al., 2019]. They strive to "realistically represent the authentic structure of the Chinese calligraphy surface" [Jian et al., 2019]. But is this "authentic structure" merely a physical imprint, or does it include something elusive that cannot be measured in three-dimensional space? Perhaps here lies the difference between imitation and genuine art.

On the other hand, there are studies attempting to analyze painting styles using stochastic models. Li and Wang, for example, investigate "characterization of pictorial art styles based on learning" [Li et al., 2004]. They note that for some painting types, such as Chinese ink painting, "only strokes provide reliable information to distinguish artists," since "there are no colors or even tones" [Li et al., 2004]. This indicates that even from a computational perspective, the uniqueness of Chinese ink painting lies in stroke dynamics and character, not just the final visual result.

Nevertheless, the question arises: can philosophical depth and cultural significance be reduced to a set of measurable parameters, even if these are 3D surface parameters or stochastic stroke models? Ledderose, in his work on mass production in Chinese art, shows how artists used standardized parts to create exquisite objects [Ledderose, 2000]. This may seem contradictory to the idea of uniqueness and individuality of each stroke, but perhaps it is just another side of the coin, demonstrating pragmatism and efficiency within certain cultural contexts.

Ultimately, the philosophical and cultural aspects of Chinese ink painting lie in its ability to bridge the material and immaterial, the visible and invisible. It offers the viewer not just an image but an invitation to reflection, contemplation, and the search for harmony. And although modern technologies can aid in studying and preserving this heritage, they are not yet capable of fully recreating the depth and multifacetedness inherent in art born from millennia of philosophical tradition. The question of how to preserve this intangible component in the digital age remains open.

Criticism and Limitations

Limitations of Technological Analysis and Imitation

Despite impressive achievements in 3D reconstruction and imitation of ink painting using neural networks, these approaches face fundamental limitations when it comes to conveying the essence of traditional art. For example, 3D reconstruction methods developed by Jian and colleagues [Jian et al., 2019] allow detailed analysis of physical stroke characteristics such as relief and texture. However, can this "authentic structure" fully encompass intangible aspects like qi (life energy) or yi (idea, intention), which are central to Chinese ink painting? If these intangible aspects were fully technologically capturable, we would likely already have algorithms capable of creating works indistinguishable from those of great masters, which remains unattainable.

Moreover, although neural networks like CalliGAN [Wu et al., 2020] can generate high-quality calligraphic symbols and imitate styles, they are essentially tools of imitation, not creativity in the human sense. They learn from existing data, identifying patterns, but lack intuition, emotional expression, or philosophical reflection that Richard Wu associates with Xie Yi painting as "cultural therapy" [Wu, 2015]. If algorithms could truly create, their works would not only imitate but also develop tradition, offering new, unexpected interpretations, which is not yet fully observed.

Insufficient Attention to Cultural Context in Western Studies

A significant portion of research, especially in computer science and engineering, focuses on technical aspects of ink, such as its physical properties, rendering methods, or style recognition algorithms [Li et al., 2004]. However, such an approach often overlooks the deep cultural and philosophical context in which ink has been used for centuries, especially in Eastern traditions. For example, in Chinese ink painting, as Ma Hu notes [Hu, 2023], "values and ideology of traditional Chinese philosophical worldview are traced in ink painting." Without understanding this connection, technical analysis risks becoming superficial, unable to explain why certain strokes or compositions have such profound meaning. If cultural context were fully integrated into these studies, we might see not just imitation but interpretation of style enriched by understanding its origins.

This limitation is especially noticeable when compared with works explicitly emphasizing cultural significance, such as in Arabic calligraphy, where ink is a carrier of sacred text [Alashari et al., 2019]. Western studies focused on the "blackest black" as a physical phenomenon [Sexton, 2021] may miss the symbolic meaning of black in various cultures, where it can signify not only absence of light but also depth, mystery, or even divine presence. Without deep immersion in cultural context, we risk reducing multifaceted art to a set of measurable parameters, losing its true value.

Conclusions

• Ink possesses a unique ability to create expressive lines and subtle tonal transitions, making it an indispensable tool for artists seeking conciseness and depth.
• Historically, ink has been used in various cultures—from ancient China to the Islamic world and the European Renaissance—for entirely different purposes, from sacred writing to anatomical sketches, demonstrating its versatility.
• The diversity of techniques working with ink (pen, brush, wash) opens broad possibilities for artistic expression, allowing creation of both strict, detailed images and expressive, atmospheric compositions.
• The monochromatic nature of ink and its contrast enable artists to focus on form, composition, and line, bypassing distraction by color, fostering dramatic and profound works.
• In Eastern traditions, especially Chinese ink painting and calligraphy, the material is inseparably linked with philosophical concepts such as Xie Yi and qi, serving not only as a means of depiction but also as a tool for expressing the inner world and meditative practice.
• Modern technologies, such as 3D reconstruction and neural networks, are actively used for analysis, preservation, and even imitation of ink painting, opening new prospects for study and education but raising questions about authenticity and transmission of the intangible component of art.
• How to preserve the philosophical depth and cultural significance of traditional ink painting in the digital age, when the emphasis shifts from manual skill to algorithmic generation, remains an open question.