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Wet-on-Wet Timing Calculator — Working Time Windows
Calculate working time windows for wet-on-wet watercolour technique based on paper weight, humidity and temperature.
How We Calculate This
This calculator estimates the working time windows for wet-on-wet watercolour technique by modelling how paper weight, humidity, temperature and pre-wetting method affect drying rates.
How it works
Base working times for the shine and damp phases are adjusted by factors for paper weight, humidity, temperature, paper size and pre-wetting method. Heavier paper, higher humidity and lower temperature all extend working time.
These windows are indicative estimates — actual timing varies with pigment load, paper sizing, airflow and brush wetness. Watch the paper's surface sheen as the definitive guide: paint flows freely while it shines, blends in a controlled way while it stays damp, and lifts or blooms once the sheen has gone.
Frequently Asked Questions
The shine phase is when the paper surface has a visible sheen of water. During this phase, paint applied will spread and blend freely with soft edges. This is the best time for large washes and blending. It typically lasts 2-5 minutes depending on conditions.
After the shine disappears, the paper is still damp but paint will spread less. Edges will be softer than dry paper but more controlled than the shine phase. This is good for adding details that should blend slightly. Working during the transition between shine and damp often causes blooms.
Yes, significantly. Heavier paper (425-640 gsm) absorbs and holds more water, giving a longer working window. Light paper (185 gsm) dries much faster and may buckle. 300 gsm is the standard for most watercolour work.
Higher humidity slows drying and extends your working window. On a dry day (30% RH) the working time may halve compared to a humid day (70% RH). In very humid conditions, you may need to help drying with a hair dryer between layers.
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Last updated: March 2026
All calculations are estimates. Always verify quantities before purchasing materials.