The Variable System of Pigment Grinding in Handcrafted Watercolor Production

In the production of handcrafted watercolor paint, grinding (mulling) is not a fixed step that every pigment must undergo. Instead, it serves as a conditional processing variable determined by the physical nature of the pigment, the material composition, and its state of combination with the binder system.

1. Criteria for Assessing Grinding Needs

• Combination State Between Pigment and Binder: Some pigments integrate directly into the liquid binder system. If distinct powdered components remain visible on the surface of the liquid system, it indicates an incomplete combination. In such cases, grinding becomes one of the options for subsequent material processing.
• Initial Particle State of the Pigment: If a pigment enters the process in a distinct clumpy or aggregated state, grinding is required to improve its particle form. If it already exists as a suitable fine powder, the processing logic differs.
• Involvement of the Binder System: The same pigment exhibits varying dispersion and combination states when introduced into different binder systems. Assessing grinding needs requires simultaneous consideration of the pigment's properties, its initial particle state, and the composition of the binder system.

2. Differences in Grinding Needs Across Paint Ranges

• Honey Watercolor Range: Certain common watercolor pigments exhibit a distinct need for grinding. However, individual variations exist even within the same range. Some colors require grinding, some need extended grinding time, and others require standing observation after being ground.
• Metallic Range: These pigments usually possess larger particle structures and exhibit good physical compatibility with water. Grinding is not a primary processing variable here. Relevant material phenomena are more likely to appear during long-term standing, as the pigment and binder separate. Re-mixing restores the material to a uniform liquid state.
• Chameleon Range: These pigments feature prominent particle characteristics and generally do not require the same degree of grinding as common watercolor pigments. Their material state depends more on the particles themselves and their separation after standing. After phase separation occurs, re-mixing restores them to a homogeneous state.
• Fluorescent Range: Significant variations exist among individual pigments within this range. Some pigments require grinding, while others do not need comparable processing. They cannot be treated as a uniform system.

3. Continuity of Grinding Duration and Intensity

There is no universally applicable or fixed grinding duration. Grinding intensity represents a continuous spectrum of material states:

• No distinct grinding required;
• A certain degree of grinding required;
• Extended grinding time required;
• Standing observation after grinding required (observing particle settling or material redistribution);
• Primary reliance on thorough mixing rather than grinding;
• Re-mixing required after long-term standing.

4. Relationship Between Grinding and Quality Assessment

• Cannot Be Judged by Final Color: Visually similar colors or colors within the same range may possess entirely different particle and combination states. Grinding needs cannot be determined solely by the final visual outcome.
• Not a Standalone Criterion for Quality: A longer grinding time does not inherently mean a better material, nor does omitting the grinding process imply incomplete production. The appropriate processing state varies from pigment to pigment.

5. Image Archiving of the Grinding Process

Portions of the grinding process and specific material states are documented and preserved as visual archives. These images and videos do not serve as tutorials, guides, or technical instructions regarding tools, timing, or operational steps. Their primary purpose is to record the actual state of a specific pigment under given conditions as a baseline for long-term material archives.

The corresponding video and visual records are archived and maintained within the Pigment Behavior collection at VHacademy as an independent archive project with paid access.