Magenta

Some posts in my Reader this morning prompted me to look at magenta, so for your delectation and delight – here first is the bloody origin of the name, then how it is made, and then some patches that I made for comparison between RGB and CMYK. And a mind bending illusion to wrap it up.

My interest is more than just curiosity for its own sake, We have our greeting cards printed by professional printing firms who print on offset machines using pigment printing ink. They ask us for a flattened PDF prepared in the CMYK colour space.

The CMYK colour space is used for printing real things like labels, book covers, greeting cards, calendars, signs, posters, billboards, etc.

CMYK is Cyan, Magenta, Yellow, and the Key colour Black. Don’t ask me why it is K for Key and not B for Black.

Professional printers printing in CMYK use offset printers that use real pigment printing ink rather than the dyes used in RGB printing.

And just to mention in passing that magenta has always bothered me because it looks artificial to my eye.

Tthe RGB colour space is made of the three primary colours, Red Green, and Blue. It is used for computer screens, TVs, and for printing on photographic paper, and and most inkjet printing.

So with that background, let’s begin with the origin of the name.

Magenta Is A Town In Italy

Magenta is a town in Italy about 25km west of Milan.

The Battle of Magenta was fought on 4 June 1859 during the Second Italian War of Independence, resulting in a French-Sardinian victory under Napoleon III against the Austrians under Marshal Ferencz Gyulai.

The second War of Italian Independence was fought between Austrian and Franco-Piedmontese armies and resulted in the annexation of most of Lombardy by Sardinia-Piedmont, leading eventually to the unification of Italy.

France’s assistance was not out of the magnanimity of its heart. A year before the war, in the Plombières Agreement, France agreed to support Sardinia’s efforts to expel Austria from Italy in return for France being given the Duchy of Savoy (in the north-west of Italy bordering France) and the County of Nice.

Making Magenta

Magenta was first made in 1856 as Fuchsine, or rosaniline hydrochloride, a magenta dye with chemical formula C₂₀H₁₉N₃·HCl.

After the Battle of Magenta in 1859, the name was changed to magenta to reflect the carnage at the battle with blood everywhere from the thousands lying dead on the battlefield.

You will never think of the colour the same again.

The Science Of Colour – Just A Brief Look

In the RGB colour wheel, magenta is opposite Green, and is therefore made from blue and red without any green.

Natural compounds of blue and red do not mix to form the colour we know as magenta, as you have probably been thinking from when you mixed those two blue and red in your paintbox. You get purple rather than magenta. And the reason is to do with the nature of reflected light in the real world.

Making Magenta In Photoshop

You may or may not know that you can make colours in Photoshop in the RGB and the CMYK colour spaces. What you see when you make CMYK is not exactly how it will print with an offset printer. That’s because you are viewing it on an RGB monitor.

So there is always a bit of an act of faith in preparing CMYK for print. One safe bet is to increase the vibrancy because CMYK generally doesn’t print as vibrantly as RGB looks on the screen.

This is because a computer screen is backlit and the colour space is additive, meaning that to get red you ‘print’ red on the screen,.

When something is printed on paper, we see it with reflected light. So printers in the CMYK colour space use the opposite subtractive primaries of cyan, magenta, and yellow. to get the opposite colours. Cyan is opposite to red; magenta is the opposite of green; and yellow is the opposite of blue.

When cyan, magenta, and yellow pigments are printed on a white background, each colour absorbs (subtracts) its opposite counterpart, `it subtracts from the reflected white light to produce the opposite colours that we see on the printed label or postcard or other product.

Strange, eh? And if you want to enjoy having your mind tell you something even stranger, see the photo at the end of this article.

RGB and CMYK Patches

I made a patch of magenta in RGB and CMYK. The proportions are easy. In RGB, magenta is a mix of 100% Red and 100% blue, both of which are produced as 255 on the intensity scale.

Then there is the fact that displaying CMYK on an RGB computer screen is its own kind of madness.

As an aside, I am just noting that the resulting patch 1500px by 750px gives a file size of just 7KB. In the CMYK colour space the file size is fifty times that. And I’ve no idea why.

Still, here are three patches.

The first is what the books say is the hexadecimal RGB for magenta, #ff00ff.

Then comes the RGB formula of 255 Red and Blue that I just mentioned.

And finally the CMYK. 

Question: Can you see a difference between the first two patches?

I promised a mind bending colour trick. Look at this photo and then look a bit closer. Click on the image to see a bigger version if you are not sure.