Material State Changes and State Documentation During the Extended Resting Period of Handcrafted Watercolor Paints

After completing initial preparation work and placing handcrafted watercolor paints into containers, their material state does not immediately cease changing. During an extended resting period, certain pigments may exhibit various physical manifestations over time.

1. Formation and Distribution Forms of Solid Structures During Resting

After extended storage in containers, some watercolor paints may gradually lose fluidity and form solid structures. In observation, this phenomenon presents distinct distribution locations and physical forms:

Container Wall Adhesion

After losing fluidity, the material forms an adhesive layer along the inner wall of the container, no longer maintaining the initial fluid state of liquid paint.

Hardened Sedimentation at the Bottom

Certain pigments with heavier particles or mineral characteristics settle toward the bottom of the container after resting. Over time, the sediment at the bottom evolves from a re-dispersible state into a dense, hard block structure.

Re-Processing of Solid Materials and Observation Records

For materials possessing conditions for further processing, the formed solid lumps can re-enter the liquid system through re-dispersion, re-grinding, or medium filtration. Re-liquefaction represents a conversion of the material's physical form and is not equivalent to restoring its initial state. Whether the material can stably combine with the binder system again and whether solid sedimentation will recur later remain subjects of ongoing observation.

2. Accumulation and Dynamic Evolution of Gas and Foam Structures

In addition to changes in solid structure, certain paints present changes in gas and foam morphology during extended resting:

Reticular Bubble Layer at the Top

Bubbles inside the paint exhibit a state of accumulating toward the upper part of the material after extended resting, forming a reticular structure or a low-density bubble layer on top of the liquid paint. This phenomenon possesses the characteristic of long-term resting, differing from temporary bubbles generated by short-term stirring.

Persistent Foam and Volume Expansion

Certain materials exhibit persistent foam accumulation, with the foam structure gradually building up in the upper part of the container. In a few observation samples under sealed storage, a phenomenon of continuous increase in bubbles or gas is observed, with the foam structure expanding toward the container outlet or even overflowing.

Boundaries of Phenomena and Exclusion of Mechanisms

Regarding the specific composition of gases, their sources, the involvement of microbial activity, or specific chemical reaction conditions, no known conclusions are documented in the absence of targeted testing. Documentation is strictly limited to directly observable phenomena: the appearance of bubbles, accumulation morphology, foam expansion, and state changes on container inner walls and outlets.

3. Multidimensional Variables Influencing Material State Changes

Phenomena occurring during the resting period are not universally present in all paints; their manifestations show associations with multiple variables:

• Differences in Pigment Behavior: Pigments with distinct mineral characteristics or heavier particles present a relatively higher frequency of sedimentation, clumping, and wall adhesion during observation. In observation samples of different pigments, gas accumulation forms also exhibit different manifestations.
• Environmental Context: Specific storage conditions, such as low temperatures, are recorded as environmental backgrounds under which phenomena occur, rather than serving independently as the sole cause of a change.
• Absence of Batch Uniformity: The same type of pigment may exhibit differences in resting behavior across different time points, moisture states, or environmental conditions, showing no absolutely fixed or unified result.

4. Conceptual Distinction Between Observation Documentation and Quality Evaluation

In material documentation, physical phenomena occurring during the resting period and product quality evaluation belong to different conceptual categories:

The container itself serves as a visual reference object: its inner wall adhesion, bottom sedimentation, top bubble layer, and outlet state provide direct visual information regarding material changes.

5. Conclusion

The extended resting of handcrafted watercolor paints in containers after completing initial preparation work belongs to an observation phase in which material characteristics gradually manifest over time.

Phenomena such as solid clumping, bottom sedimentation, reticular bubble layers at the top, and foam accumulation objectively reflect state changes of different pigments under specific time, environmental, and container conditions. In the absence of specialized testing data, archives preserve only factual records based on direct observation and do not establish explanations for unverified mechanisms. These state changes arising over time are documented, organized, and compared, forming the content of the long-term material archives for handcrafted paints.