What ratio of medium to paint should I use for glazing?

A common starting ratio is 1 part paint to 4 parts glazing medium. This gives a transparent, luminous layer. For very transparent glazes, go up to 1:6, or to Liquitex’s official 1:10 with their Glazing Medium for maximum flow. Use a gloss medium for the most clarity. Liquitex Glazing Medium, Winsor & Newton Galeria Glaze Medium and Golden Glazing Liquid are all available in UK art shops.

How much medium do I add for impasto painting?

For impasto, add heavy gel medium at roughly 1 part gel to 2 parts paint (ratio 0.5) so you extend the paint while keeping body and texture. Heavy body gels from Golden, Liquitex or Daler-Rowney System 3 work well. You can also use modelling paste for even thicker, sculptural textures.

What is the best pouring medium ratio?

For acrylic pouring, use roughly 1 part paint to 2-3 parts pouring medium so the mix flows like warm honey. Liquitex Pouring Medium is popular, while Floetrol (a paint conditioner from DIY shops) is a budget-friendly alternative widely used by UK pour artists. Adjust by eye until it ribbons off the stick without breaking.

Do I need to add water as well as medium?

With acrylics, a small amount of water (5-10% of the mix) improves flow without weakening the film, but for durability Golden recommend diluting with acrylic medium rather than water because medium carries binder. Keep water under about 25-30% of the acrylic mix. With oils, use solvent (turps or Zest-It) instead of water. Medium alone is usually sufficient for most techniques.

How do I use this calculator for watercolour?

Select Watercolour as the paint type and the calculator treats the ratio as paint-to-water dilution rather than an added polymer or oil medium — watercolour is thinned with water on white paper, not bulked with a medium. A higher ratio means a paler, more transparent wash; near-neat paint gives the most intense colour. No glazing, pouring or gel medium is needed.

ArtCalcs

Paint-Medium Ratio Calculator — Glazing, Impasto & Pouring

Calculate medium-to-paint ratios for glazing, impasto, pouring and other painting techniques.

TechniqueSets the default medium-to-paint ratio for this technique

Paint TypeOil adds a fat-over-lean note; watercolour switches to water dilution

Paint Volume

How much paint (ml) you want to start from

Number of Coats

Layers you plan to apply — splits the mix per coat

How We Calculate This

Calculates the volume of medium (or, for watercolour, water) to add to your paint based on the selected technique and desired ratio.

Formulas

Medium volume = Paint volume × Ratio (acrylic/oil)
Watercolour: Water volume = Paint volume × Ratio (no polymer/oil medium)
Extra water = (Paint + Medium) × Water percentage
Total mix = Paint + Medium + Water
Per-coat volume = Total mix / Number of coats

Coverage figures are indicative only — real spread depends heavily on wet-film thickness, brush, surface and absorbency. Treat them as a sanity check, not an exact yield.

Frequently Asked Questions

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Last updated: March 2026

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