Quinacridone Rose

What color is quinacridone rose?

The story of quinacridone rose

Quinacridone rose is the pink in your printer, and it took sixty-two years to get from a Polish lab bench to a tube of paint.

In 1896 the Polish chemist Stefan Niementowski reacted phloroglucinol with anthranilic acid and called the product quinacridone, a mash-up of quinoline and acridone. Later work showed his compound was a bent cousin of the one painters use. The straight, five-ring version was first made in 1935 by Hans Liebermann, and then nothing much happened for twenty years. It was a red-violet powder with no job.

DuPont gave it one. In 1955 the company's chemists found two new ways to make the molecule and noticed that it crystallizes in several forms, each a different color. Pack the molecules in a criss-cross lattice and you get the gamma form, a clean bluish red: quinacridone rose. Pack them in straight chains and you get the beta form, a maroon red-violet: quinacridone violet. Same molecule, two colors, depending on how it stacks. The first quinacridone pigments went on sale in 1958, made for car paint, which has to sit in the sun for years without fading. Painters got them as a side effect.

Chemists then started swapping atoms on the ends. Two methyl groups give PR122, quinacridone magenta, a very bluish pink. Two chlorines in another position give PR209, a brighter, warmer red. Fuse quinacridone with its own oxidized twin, quinacridone quinone, and you get the duller maroon and gold versions, PR206, PO48 and PO49. The gold, PO49, has since been discontinued, so if a tube says quinacridone gold today, turn it over and read which pigments are doing the work. The rose and the magenta, meanwhile, finished off the madder reds: alizarin crimson and rose madder both fade, and the permanent versions of both sold today are built on quinacridones.

Then there is the printer. The four-color process, cyan, magenta, yellow and black, was worked out in the 1890s when newspapers wanted color comics. Magenta itself began as an aniline dye of 1859, renamed after a battle in northern Italy to help it sell. Today the most common magenta printing ink is a dispersion of quinacridone crystals ground down to nanometer size. The pink in a photo print and the pink on my palette are, chemically, the same stuff.

Here is why I care. For most of history the clean cool red was the weak link in every paintbox: madder faded, and so did the alizarin made to replace it. Quinacridone rose is a cool red that does not fade, does not granulate, and makes purples with ultramarine that look like they came out of a tube. It is not romantic. Nobody dug it out of a hillside or boiled it out of a root. It came off a production line in 1958 and it is the best thing that ever happened to my violets.

Pigment facts

These describe the pigment in general. Every brand's tube behaves a little differently, so test yours on scrap paper.

How to mix quinacridone rose

You cannot mix quinacridone rose from other colors; a mixed red is always duller than a single pigment, and this one is about as clean as red gets. What you can do is mix outward from it. A touch of a warm red turns it into a permanent alizarin; a speck of yellow ochre turns it into rose madder; thinned to nothing it is the pink in a cheek.

Ultramarine is the pairing that matters: ultramarine and rose both carry a little violet already, so together they make the cleanest purples in watercolor, from lavender to plum depending on the ratio. With phthalo blue you get a colder, electric violet; with a lemon yellow, a surprisingly clean coral.

Using quinacridone rose in watercolor

Use quinacridone rose for anything pink or cool red that has to last: flowers, skin, sunsets, the shaded side of a red object. In a thin wash it is the freshest pink I own; at full strength it is a deep rose that reads as crimson from across the room.

Glazing is its natural technique. Because it is transparent, a wash of rose over a dry passage tints everything underneath without muddying it: over a pale yellow it makes a glowing orange, over a pale blue a violet with light in it. Let each layer dry before the next.

It pairs with the blues and the greens. Beside Twilight Indigo or Glacier Blue it looks warmer and pinker; mixed with Forest Green it makes a soft, transparent dark that is my usual replacement for black.

One thing I learned the hard way: it does not lift. I once tried to scrub a rose wash back to white for a highlight and got a pale pink stain and a fuzzy patch of paper. Now I paint around the whites or mask them first. With a staining color, the plan has to happen before the brush does.

Quinacridone rose vs quinacridone magenta (and alizarin crimson)

PR122, quinacridone magenta, is the same molecule with two extra methyl groups, and the effect is a step toward blue: a cooler, more violet pink that leans toward purple where rose leans toward red. Side by side, magenta looks like printer ink and rose looks like a flower. Magenta makes the cleaner purples; rose makes the more believable reds and skin.

Alizarin crimson is the color rose replaced. Genuine alizarin is warmer, browner and darker in the tube, and it fades; tubes labeled permanent alizarin are now quinacridone with a warmer red added. If you own one, you already own a quinacridone.

If quinacridone rose is a raspberry, quinacridone magenta is the same raspberry under a blue light, and alizarin crimson is the jam.

More color stories

Mel, founder of Tobio'sI make portable watercolor kits and I named the company after my cat. I write these pages for the beginner I used to be, one pigment at a time.