Impact of Environmental Seasons on the Process and Drying of Handmade Watercolors: A Long-Term Observation Record

In handmade watercolor systems, the entire journey—from raw material mixing and pan filling to natural drying and final form stability—takes place under open environmental conditions. Continuous making, tracking, and parallel comparisons across multiple color systems under the local climate in Germany show that temperature and humidity fluctuations brought by seasonal changes act as important environmental variables affecting both drying behavior and production rhythm.

Among all processing steps, seasonal factors exert the strongest influence on pan filling and the natural drying phase.

1. Differentiated Impacts of Seasons on Different Binder Systems

Different binder formulations and pigment systems show noticeably different degrees of response to environmental seasonal shifts.

• Honey Watercolor System (including standard watercolors and fluorescent watercolors): The honey watercolor system (which shares the same binder foundation across standard colors and fluorescent colors) exhibits the highest sensitivity to seasonal changes.
  • High-heat drying periods (summer and late summer to autumn transition): During periods with high ambient temperatures and relatively low humidity, natural drying accelerates significantly. Moisture on the paint surface evaporates rapidly, forming a dried outer crust prematurely while the inner material still retains high water content.
  • Visual structural behavior: This timing gap between surface drying and core drying leads to lower-density regions or internal cavity structures inside the paint pan. Such phenomena occur with higher probability during the hottest, driest summer stretches and in warm transitional periods leading into autumn.
  • Varying pigment sensitivity: Internal cavities do not appear uniformly across all colors. The structural characteristics of individual pigment particles determine how they react to environmental conditions: some pigments are highly sensitive to hot, dry air and show higher cavity rates, while others maintain a relatively stable drying form.
  • Need for manual checking and intervention: A rapidly hardened surface does not guarantee a completely stable interior. During these seasons, the process relies on more frequent manual inspections and maintenance steps to prevent structural defects caused by internal cavities and avoid later rework.
• Metallic and Chameleon Watercolor Systems: Compared to the honey watercolor system, metallic and chameleon watercolor systems demonstrate higher overall environmental stability over years of long-term tracking.
  • Shifts in drying rhythm: During summer and warm, dry periods, drying speeds up for these systems as well, shortening the overall production cycle; during cool or humid periods, the drying process slows down accordingly.
  • Structural stability: Although drying rates fluctuate with environmental conditions, no clustered internal cavities or abnormal structural issues caused by rapid drying were observed in these systems across any season. The change in drying speed merely alters the production timeframe and shows no negative correlation with the final form stability of the finished product.

2. Stage-by-Stage Drying Characteristics Across Seasonal Transitions

The impact of seasonal changes on material formation progresses gradually through clear phases:

• Spring: The environment transitions from lower to higher temperatures. Temperature and humidity fluctuate frequently, causing paint drying speeds to adjust in steps according to daily and weekly weather changes.
• Summer and Summer-to-Autumn Transition: Sustained high temperatures and low humidity create a concentrated period of accelerated drying. The timing gap between fast surface hardening and lagging interior moisture reaches its peak, making this the primary observation window for internal density anomalies in the honey system.
• Autumn: The environment transitions toward lower overall temperatures. However, late summer and early autumn periods may still briefly display high temperatures and dry air, meaning differences between surface and core drying are still recorded during this phase.
• Winter: Overall ambient temperatures drop, causing natural evaporation rates to slow down and significantly extending the production cycle. The longer drying window allows moisture to escape more evenly, though it substantially increases the total time investment.

3. Connecting Environmental Variables to Production Schedules and Material Archives

Seasonal shifts alter both the available time windows and the physical environmental conditions during natural material formation.

• Practical scheduling value: Given the distinct behaviors of different systems across seasons, allocating filling schedules for specific color systems and pigments according to seasonal climate features helps lower the rate of internal defects caused by uneven drying, reducing adjustment work and rework costs.
• Building material archives: Long-term comparisons of drying data collected under specific environmental conditions (such as the climate in Germany), across seasons, pigments, and binder systems, help clarify whether structural anomalies stem from intrinsic pigment properties or from the overlap of external environmental variables.

Video footage documenting select steps of the handmade watercolor making process and pigment behavior is archived at VHacademy (an independent project researching material behavior, accessible via paid subscription).