OXIDIZING EMULSIONS

Developer creams: a guide to volumes and mixing ratios

Developer cream is hydrogen peroxide in a creamy form that's mixed with hair colour or bleach. It has two jobs: it opens the cuticle to let pigments penetrate, and it oxidises natural melanin, determining how much the hair can lighten.

Tre Pi Profumerie stocks 10, 20, 30 and 40 volume developers from the leading professional lines — L'Oréal Professionnel, INOA, Wella, Matrix, Barex, Helen Seward, Koster, Hair Tech, Taboo and Altissima — in salon sizes. Save up to 60% with our trade price list, no minimum order, delivery in 24-48 hours.

Volumes and percentages: the table

The conversion is simple: volumes ÷ 3.3 = percentage. A 20 volume developer is 6%, a 40 volume is 12%.

How to choose the right volume

Grey coverage

20 volume is the standard. You need enough cuticle lift to deposit pigment into hair that has none of its own. With 10 volume, coverage is often incomplete, especially on glassy, resistant grey hair around the hairline.

Tone-on-tone

10 volume, or 5 volume if the line offers it. There's no need to lift: the pigment deposits and gradually fades with washing.

Darkening

Always 10 volume. A higher volume lifts before it deposits, giving a warmer result than intended.

Lightening with permanent colour

30 volume for 2-3 levels, 40 volume with high-lift colours. Beyond 4 levels, colour alone isn't enough: you need bleaching followed by toning.

Regrowth and lengths

On regrowth, use whatever volume the lift requires; on lengths that are already coloured, drop to 10 volume to avoid over-processing. Using the same volume everywhere is the most common cause of dull lengths and porous ends.

Mixing ratios

• Permanent colour — usually 1:1 (30 g of colour + 30 ml of developer)
• High-lift colours — 1:1.5 or 1:2, to boost lifting power
• Tone-on-tone and semi-permanents — often 1:1.5 or 1:2, with low-volume developers
• Bleaching powder — generally 1:2, thicker for freehand techniques, more fluid for foil

Ratios vary by brand and by line: always check the product's technical sheet. Mixing by eye is the most frequent cause of inconsistent results from one service to the next.

Developers by line, in our catalogue

Each brand makes its own developer, formulated to match its specific colour system. Using a developer from another brand is possible in an emergency, but it alters processing time and how the shade develops: viscosity, pH and stabilisers are all calibrated to that particular line.

• L'Oréal Professionnel — Oxydant Crème 10, 20, 30 and 40 volume. With Majirel, the standard ratio is 1:1.5; with the high-lift Majirel High Lift and Blond Studio it goes up to 1:2.
• L'Oréal INOA — requires Oxydant Riche INOA, not the classic Oxydant Crème. This is an ammonia-free, oil-delivery system and the ratio is 1:1. Swapping in the standard developer compromises how the ODS technology works and affects coverage.
• Wella — Welloxon Perfect 6%, 9% and 12%. With Koleston Perfect the ratio is 1:1, with Blondor it goes up to 1:1.5 or 1:2. Color Touch uses its own Emulsion at 1.9% or 4%, not Welloxon.
• Matrix — Cream Developer 10, 20, 30 and 40 volume. With SoColor the ratio is 1:1; with the Ultra Blonde range it moves to 1:2.
• Barex — dedicated developers for the Permesse and Joc Color lines.
• Helen Seward — cream developers for the brand's colour system.
• Koster — professional developer creams in the standard volumes.
• Hair Tech, Taboo and Altissima — Italian lines with dedicated developers, available in salon sizes.

The ratios given here are the most common ones for each brand's main lines. Individual ranges may have their own ratios: the product's technical sheet remains the reference to follow.

Storage and safety

Hydrogen peroxide is unstable: it breaks down with light, heat and contamination. A few practical rules:

• Keep bottles closed, upright, away from light and below 25°C.
• Never pour leftover product back into the original bottle: it contaminates it and speeds up degradation.
• Use non-metallic bowls and spatulas. Metals catalyse the breakdown of peroxide.
• Use the mixture straight away: it loses effectiveness within minutes of being prepared and cannot be stored.
• A developer that has lost its lifting power gives warmer, less opaque results. If a bottle has been open for a long time, it's best to replace it.
• Gloves are a must. 40 volume is irritating to skin and mucous membranes and should never be applied directly to the scalp.

Frequently asked questions

What's the difference between 20 and 30 volume?

20 volume (6%) lifts 1-2 levels and is the standard for grey coverage. 30 volume (9%) lifts 2-3 levels and is used when you need to raise the base level. With the same colour, 30 volume gives a lighter, warmer result.

Can I use 40 volume on the scalp?

No, not applied directly. 40 volume is used with bleach in techniques that keep distance from the scalp, or with high-lift colours according to the manufacturer's instructions.

Can two different volumes be mixed together?

Yes, many lines allow this to get intermediate volumes. Mixing equal parts of 10 and 30 volume gives you a 20 volume. It's common practice when the volume you need isn't available, as long as you stay within the same line.

Does developer expire?

Yes. Unopened and stored correctly it generally lasts 3 years from manufacture; once opened, its effectiveness declines gradually. Degraded developer is the hidden cause behind many disappointing lifts.

Cream or liquid developer?

Cream emulsions have a viscosity that makes them more stable to apply and reduces dripping. Liquid formulas are mainly used in very fluid mixtures or for certain specific techniques.

How much developer do I need for a service?

For a regrowth application on short hair, around 30-40 ml; for a full application on medium-to-long hair, 60-90 ml. A 1000 ml size covers on average 12-30 services, which is why it's the most economical choice for salons.

Related products

• Professional hair colour
• Bleach and lightening powders
• Ammonia-free hair colour
• Semi-permanent colour
• Colour glosses
• Bowls, brushes and technical accessories

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