Dust as an External Variable in Material Behavior

In long-term observations of materials such as alcohol ink, powder pigments, solid watercolors, acrylics, and oil pastels, external dust is a continuously present environmental factor.

Dust is neither an inherent component of the materials nor an intentionally added substance. However, as long as materials are in an open environment, dust may enter their behavior process. The impact of dust is not fixed; its degree of influence depends on the state of the material at the time (sealed containers, open liquids, wet states, or fully solidified), the size specifications of the dust itself (fine particles or foreign objects such as hair), and the visual characteristics of the materials (such as color depth and opacity).

1. Alcohol Ink System

• Sealed Container Stage: When alcohol or alcohol ink is in a sealed container, external dust remains only on the outer walls and cannot enter the liquid, having no direct impact on internal material behavior.
• Open Behavior Stage: After ink enters an open space, airborne microparticles drop into the liquid. Even tiny dust particles become localized disturbance points during ink flow, diffusion, and line formation, causing breaks in otherwise continuous lines or leaving foreign object traces in the flowing structure.
  • Source Characteristics: This phenomenon repeatedly appears in open-environment observations. Beyond inherent airborne particles, air movement generated by the operator's clothing, desk surface, and tools like heat guns alters the motion state of surrounding particles, causing them to enter the material system.
• Formed Surface and Preservation: Different substrates show distinct variations in dust adhesion. On surfaces with weaker adhesion, dust settling results in shallow visible traces; direct physical wiping of a formed surface will itself break the established ink structure.

2. Powder Pigments and Processing

• Sealed Storage and Unopened Stage: When powder pigments are stored in sealed containers, external dust does not enter in large amounts. Microparticles already present in raw materials before opening cannot be visually distinguished from the pigment itself in later observation. Because the pigment itself is powdered, fine dust blends visually with the original particles upon entering; conversely, larger foreign objects such as human or animal hair present clear visual distinctness.
• Transfer and Stirring Process: When powder is taken from a container and mixed with binders, the material transitions from a powder state to a liquid state. Because of exposure to air and localized airflow created by stirring, the probability of dust entering increases.
• Visual Perception Differences:
  • High Opacity and Dark Pigments: Low visual sensitivity to fine dust; fine particles mixed in are usually difficult to distinguish visually.
  • High Transparency and Light Pigments: High visual sensitivity to colored or foreign dust; particles of the same size are more easily observed in the final presentation.

3. Solid Watercolor System

• Material Properties and Humidity Response:
  • Environment-Insensitive Materials: The surface remains stable after drying; dust stays on the surface after settling, and dust removal processes cause no changes in material state.
  • Humidity-Sensitive Materials: In high-humidity environments, the surface easily absorbs moisture to soften or reactivate. Dust dropping onto the surface at this time binds with the softened layer, embedding into the material surface layer and showing a deposition state completely different from a dry, stable surface.
• Dynamic Intervention During Painting: During painting, hair or larger particles enter the image with wet paint on the brush. If the material remains wet, foreign objects leave traces on the wet film; even if the foreign object is removed later, localized bumps or texture marks may still remain after drying.
• Preservation and Cleaning Methods: During long-term preservation, without sealed measures to block dust, dust continuously accumulates on the surface. When cleaning a formed artwork surface, the method and force of using wiping tools directly alter the structural integrity of the surface.

4. Acrylic System

• Differences Between Microparticles and Foreign Objects: Due to the high opacity of acrylics, fine dust particles mixed into wet paint usually fail to form clear visual recognition. However, longer linear or larger foreign objects like human or animal hair drop in to stay directly on the surface or embed in the paint, forming clear line-like traces.
• State After Curing into a Film: After acrylics dry completely, they form a continuous and lustrous film structure. If hair is fixed into the film body before drying, its trace remains in the structure; if the paint dries completely, the material is no longer reactivated by water, and subsequent dust settling on the film surface stays mainly on the outer surface layer, where cleaning actions typically do not cause lasting changes to internal material structures.

5. Oil Pastel System

• Long-Term Interventions and Adhesive Characteristics: Oil pastels are solid materials that maintain a degree of stickiness and can be reactivated over long periods. When left in open spaces, dust continuously adheres to the surface.
• Mixing and Spreading Process:
  • Fine Particles: Thanks to the high opacity and textured grain of oil pastels, fine dust has limited impact on the visual effect.
  • Hair and Foreign Objects: When large particles or hair fall in, they directly participate in the final surface structure during physical shaping like color mixing and spreading.
• Post-Preservation and Protection Divisions:
  • Unprotected State: Artworks without an isolation film continuously accumulate dust when exposed long-term to open spaces. Because the oil pastel surface layer remains long-term in a state capable of reactivation or physical displacement, accumulated dust becomes extremely difficult to clean and causes damage to the picture structure. Therefore, artworks without an isolation film stay in a sealed, isolated storage state.
  • Protected State: After applying an isolation film, the protective layer cuts off direct contact between dust and the oil pastel surface layer, allowing the artwork to present a state capable of being exposed to external environments.

6. Summary of Dust Variable Action Mechanisms

Based on long-term observation records, the effects of external dust on the aforementioned art material behaviors divide into the following dimensions:

1. Medium State: Sealed containers block dust; open liquids and wet surface layers easily absorb and embed dust; completely dry, non-reactvatable hard surface layers experience only surface settling.
2. Particle Size: Microparticles easily blend into high-opacity or color-matching particle systems; large foreign objects like hair directly constitute visual traces.
3. Optical and Visual Characteristics: High-transparency and light-colored areas have higher visual sensitivity to dust than dark-colored, high-opacity areas.
4. Surface Reversibility: For materials that can resoften, reactivate, or retain long-term stickiness (such as watercolors in high humidity, oil pastels), dust binds deeply with them, and subsequent manual cleaning easily causes surface damage; for surface layers with high structural stability and irreversibility (such as dry acrylics), dust exists only as static surface deposits.

As an objectively existing external variable in open operation environments, whether external dust produces observable changes in material behavior and results depends on the combined effect of dust size, existing material state, visual characteristics, and preservation environment.