Ink Chromatography

[etoyoc]

I was cleaning some Diamine Pumpkin off of my skin after a refill, and was noting the red color that wouldn't wash off and the yellow that ended up on my coffee filter. So, on a whim, I did a quick chromatography example of Diamine Pumpkin. As most of us learned in elementary school, orange is yellow + red. Here is some photo evidence.

 

http://1.bp.blogspot.com/_LYK0_Zfsz9s/TNPxD3phq6I/AAAAAAAABI0/7hIpmG5-XoA/s1600/2010-11-05_06-54-44_572.jpg

 

This is something I can easily do with other inks as well and will probably include on any ink reviews that I ever get around to accomplishing.

[Sandy1]

Hi,

 

I agree that Red + Yellow gives Orange.

 

But...

 

Red is composed of Magenta + Yellow.

 

The colour on the right-hand side of your image is Magenta not Red.

 

So the Pumpkin contains a ratio of Magenta to Yellow which gives Orange.

 

I find counter-top chromatography especially useful when looking at the darker inks.

 

Also, be aware that different dye-stuff has variable levels of water solubility - I rather doubt this method would reveal much about inks that are highly water-resistant.

 

Bye,

S1

Edited November 5, 2010 by Sandy1

[etoyoc]

Hi,

 

I agree that Red + Yellow gives Orange.

 

But...

 

Red is composed of Magenta + Yellow.

 

The colour on the right-hand side of your image is Magenta not Red.

 

Also, be aware that different dye-stuff has variable levels of water solubility - I rather doubt this method would reveal much about inks that are highly water-resistant.

 

BINGO! Good observation and right to the point that I left off.

 

You are quite correct about the dye being magenta and yellow. I guess I shouldn't do a quick post without checking for completion. With my students this would then be a jumping off point for why photo quality printers often use cyan and magenta (or even why when mixing light instead of ink, green becomes a primary color - but that is a different lab).

 

You are also correct about the water solubility of different dyes. However as a standard of comparing inks using 2-3 solvents, it can be fairly useful for general knowledge. There are also some inks (fraud/bullet proof) that I doubt I would be able to get any color separation on at all. But then again, even those results (or lack thereof) would be results that could be useful.

Edited November 5, 2010 by etoyoc

[Mickey]

Hi,

 

I agree that Red + Yellow gives Orange.

 

But...

 

Red is composed of Magenta + Yellow.

 

 

Maybe yes, maybe no, depending on the choice of primaries and whether one thinks in additive or subtractive terms. Primary schemes other than CMY (e.g., RYB) are possible, although they will yield different gamuts. Red can be composed from Magenta and Yellow (Yellow = -Blue) or it may simply be Red, as it would be in an RYB system, where pumpkin would be some combination of R + Y.

 

Ultimately, real world inks are created from practical dyes (i.e., ones that are stable and cheap) which will both play well together and produce the desired colors; in the case above enough yellow dye was added to a magenta dye to pull (subtract) the result past the red(s) to pumpkin-orange.

[LPS]

Typically dyes and pigments use Cyan Magenta and Yellow and Black if extra density is needed.

These colors are subtractive. They absorb 1/3 of the light spectrum and pass the other 2/3.

 

If we break white light into regions defined as Red Green and Blue, the following will occur.

Magenta: Absorb Green Pass red and blue light

Cyan: Absorb red and padd green and blue light

Yellow: absorb blue and pass red and green light

 

Black absorbs all.

[Surnia]

I've done that too, you should take a look at PR's Avacado if you get the chance, runs from red, yellow, green, then blue. The red component does run a bit, while on paper the red component's decently permanent when written with.

 

Diamine's Orange does the same kind of run, with the exception that the magenta is slightly different in shading.

[Sandy1]

Hi,

 

I agree that Red + Yellow gives Orange.

 

But...

 

Red is composed of Magenta + Yellow.

 

 

Maybe yes, maybe no, depending on the choice of primaries and whether one thinks in additive or subtractive terms. Primary schemes other than CMY (e.g., RYB) are possible, although they will yield different gamuts. Red can be composed from Magenta and Yellow (Yellow = -Blue) or it may simply be Red, as it would be in an RYB system, where pumpkin would be some combination of R + Y.

 

Ultimately, real world inks are created from practical dyes (i.e., ones that are stable and cheap) which will both play well together and produce the desired colors; in the case above enough yellow dye was added to a magenta dye to pull (subtract) the result past the red(s) to pumpkin-orange.

 

Hi,

 

I have no idea of or interest in alternate systems such as RYB, and do not see how they are relevant to the OP.

 

I certainly agree that 'practical dyes' are used for most commercial industrial processes. And it seems to me that the proliferation of consumer /SOHO-generated colour prints has lead to adoption & proliferation of CMY+K systems.

 

A good friend does textile dye-ing with natural (non-aniline) dyes. She achieves amazing colours + visual effects just not possible from CMY+K. Same for FP inks: they're not just CMY+K dyes. (Reference the yarn of bringing True Blue to market.)

 

Bye,

S1

[Mickey]

Hi,

 

I agree that Red + Yellow gives Orange.

 

But...

 

Red is composed of Magenta + Yellow.

 

 

Maybe yes, maybe no, depending on the choice of primaries and whether one thinks in additive or subtractive terms. Primary schemes other than CMY (e.g., RYB) are possible, although they will yield different gamuts. Red can be composed from Magenta and Yellow (Yellow = -Blue) or it may simply be Red, as it would be in an RYB system, where pumpkin would be some combination of R + Y.

 

Ultimately, real world inks are created from practical dyes (i.e., ones that are stable and cheap) which will both play well together and produce the desired colors; in the case above enough yellow dye was added to a magenta dye to pull (subtract) the result past the red(s) to pumpkin-orange.

 

Hi,

 

I have no idea of or interest in alternate systems such as RYB, and do not see how they are relevant to the OP.

 

I certainly agree that 'practical dyes' are used for most commercial industrial processes. And it seems to me that the proliferation of consumer /SOHO-generated colour prints has lead to adoption & proliferation of CMY+K systems.

 

A good friend does textile dye-ing with natural (non-aniline) dyes. She achieves amazing colours + visual effects just not possible from CMY+K. Same for FP inks: they're not just CMY+K dyes. (Reference the yarn of bringing True Blue to market.)

 

Bye,

S1

 

My post didn't apply directly to the OP, but it did to your statement "Red is composed of Magenta + Yellow." Red can be produced by combining Yellow with Magenta (but it is not really composed of those colors), and it can also be produced using other primaries (such as the red-orange, green and blue-violet used in the autochrome process), or by simply being Red, a range of colors (630–740 nm).

 

In fact, any three colors can be used as primaries, though some trios are obviously not very useful. The question is whether the gamut available from the primaries includes the colors you want and at a desirable price. I suspect, as much as anything, that the CMY (with or without a Key) has proliferated because stable dyes approximating the theoretical values for those colors are cheaper than those for a roughly comparable RYB system, a system I believe most people find more intuitive.

 

You're quite right regarding textiles, ink, etc. The nominal color (as we say over here) is only part of the story. (Fun stuff) BTW, you might actually find the Wiki article on the history of Technicolor pretty interesting reading.