Four tubes of modern high-chroma pigment, and the discipline they require
Phthalo blue, quinacridone magenta and hansa yellow are among the most lightfast, most permanent pigments ever made. They are also the most dangerous things in a beginner's paint box, because their tinting strength is between five and twenty times that of the traditional pigments they sit next to.
Rose — Transparent cool red with a violet lean.
| Pigment | Parts | Hex |
|---|---|---|
| Phthalo Blue Green Shade | 1 : 4 (25%) | #1F5E7A |
| Quinacridone Magenta | 1 : 4 (25%) | #A32E5E |
| Hansa Yellow Medium | 1 : 4 (25%) | #E8C42A |
| Perylene Maroon | 1 : 4 (25%) | #7B3A38 |
Mixing notes
| Vivid green Three percent. Not a misprint — these pigments are so strong that a normal load produces a black. | 1 hansa yellow + 1 phthalo blue green shade, at 3% load | #1E9A6A |
| Electric violet Staining and unmovable. Once on the paper, this is the colour; plan it before you lay it. | 2 magenta + 1 phthalo blue | #6B2F9E |
| Deep warm red The maroon is the only member of the set with a low tinting strength; it is here to provide a dark that is not a black. | 2 magenta + 1 perylene maroon | #8E2A34 |
| Neutralising duo Any two of the three high-chroma pigments neutralise instantly. There is no gentle middle with this set. | 1 vivid green + 1 electric violet, at 5% load | #6E6A5E |
- Dilute all four pigments to 10% before you start. Never work from the tube with phthalo or quinacridone.
- Paint a 3 x 3 grid of the three primaries at 3%, 6% and 12% load. Note how little difference there is between the rows.
- Mix each pair and record whether the result is usable or immediately neutral. With this set, expect most pairs to neutralise.
- Paint one small saturated study using at most two pigments per passage, and never more than two passages touching.
- Check the study under daylight. Phthalo blue and quinacridone magenta both shift substantially under tungsten, and the shift is large enough to change a decision.
- Keep a separate small well palette for these four. Contamination from an earth pigment will deaden the whole set within one session.
- Wash the wells with soap rather than water. Quinacridone leaves a film that water alone will not remove.
Tinting strength changes the whole method
Traditional watercolour practice assumes you can take a loaded brush from the well and put it on paper. With phthalo blue at full strength, that produces a near-black in one stroke and there is no way to lighten it — the paper is stained. The working load for all three modern high-chroma pigments is between 3% and 12%.
This is not a personal preference. Commercial pigment data sheets list phthalo blue's tinting strength at roughly twenty times that of French ultramarine by weight, and quinacridone magenta at six to eight times alizarin crimson.
They neutralise instantly, and that is useful
The reason these pigments feel uncontrollable is that any two of them mixed produce a neutral almost immediately. There is no gradual approach from saturated to grey — the transition happens over a very narrow ratio band.
Once that is understood it becomes an advantage: you can neutralise a passage with a quarter brush-tip rather than a full one, which means large areas can be greyed without adding water and disturbing the wash.
Quinacridone permanence has a maintenance cost
Quinacridone magenta is a staining pigment with very high permanence: once it bonds to the paper it is there for the life of the sheet. That is exactly what you want in a finished painting and exactly what you do not want in a palette.
It also leaves a film in a porcelain well that plain water will not lift. Use a separate well tray, wash it with soap at the end of every session, and never let it dry in the well — a dry quinacridone film takes a plastic scraper to remove and will contaminate the next mix.
What matters
- Working load for phthalo, quinacridone and hansa pigments is 3% to 12%, never straight from the tube.
- Any two of the three modern primaries neutralise almost immediately — a narrow ratio band, not a gradual shift.
- That narrow band is useful: a quarter brush-tip greys a large area without adding water.
- Use a separate well tray and wash with soap; a dry quinacridone film will contaminate the next mix.
Handling note — Technique notes only. Follow the manufacturer's safety data sheet for pigment handling and studio ventilation.