What ratio of paint to water should I use?

For very light washes, use 1:30 (paint:water). Light washes 1:15. Medium 1:8. Strong 1:4. Very strong 1:2. These ratios produce noticeably different tonal values when dry.

Why does watercolour dry lighter?

Watercolour paint contains pigment suspended in a water-soluble binder. As the water evaporates, only the pigment remains on the paper. The wet paint always looks darker than the dry result — typically 20-30% lighter when dry.

How does technique affect dilution?

Wet-on-wet painting dilutes further as it hits wet paper (use less water in your mix). Glazing needs very dilute layers to maintain transparency. Dry brush uses thicker paint with minimal water for textured effects.

Can I add more water to a dry wash?

Adding water to a dry wash (lifting) lightens it but may disturb the pigment. Some pigments are staining and resist lifting. If you need a lighter wash, it is better to start with more water in your initial mix.

How do I test my dilution before painting?

Always test on a scrap piece of the same paper you are using. Apply a swatch and let it dry completely (use a hairdryer to speed this up). Watercolour dries 20-30% lighter, so your test must be fully dry to judge accurately.

ArtCalcs

Watercolour Dilution Calculator — Paint to Water Ratios

Work out paint-to-water ratios for different wash strengths and techniques.

Paint Amount

Concentrated paint from tube/pan

Target Strength

Technique

How We Calculate This

How Dilution Calculation Works

Water = Paint amount x Dilution ratio x Technique factor

The base dilution ratio depends on target strength. Wet-on-wet technique reduces the water (paper already supplies moisture). Glazing increases water for maximum transparency. Dry brush uses minimal water.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify quantities before purchasing materials.