Any Violet Inks That Are Violet Wavelength?

[XYZZY]

Does anybody know if there are violet inks that are actually what a physicist would call violet? I.e. with color in wavelength 400 - 450nm?

 

As opposed to purple or red-blue mixes that correspond to violet on a color wheel?

 

Why? Because the trickiness of violet color reproduction in the digital age amuses me.

[mke]

Why don't you show a picture of such a color?

[XYZZY]

Why don't you show a picture of such a color?

 

TLDR: JPG files and computer displays cannot differentiate these, so it's not possible to do what you ask.

 

Long answer:

 

The human eye has cones that pick up red, green, and blue, although they pick up wide bands: red picks up deep red down to (almost) infrared, and all the way up into oranges and yellow. Similarly green picks up more than green, and blue more than just blue. We also have rods that pick up brightness (i.e. black & white vision), but the rods aren't interesting to this.

 

When we see cyan light, it's triggering both green and blue cones. Our brain mixes that to perceive cyan.

 

When we see purple, it's triggering both blue and red. Our brain perceives purple.

 

When we see violet (the kind I'm looking for, at wavelengths shorter than blue), the blue cones pick it up. But, curiously, the red cones also pick it up violet. The end result is that as far as human vision is concerned, violet and purple are the same thing: red and blue. And artist's color wheel will tell you then violet is a different shade than purple. But that's basically the same as arguing about reddish purples or blueish purples.

 

As for computer displays: they emit red, green, and blue of specific colors. It's a specific blue. But the mixing works similarly: while a computer cannot directly produce cyan: it instead turns on some blue, and turns on some green, and our brain ends up getting the same signals as if we were really seeing light of the wavelength for cyan.

 

A computer display cannot emit a true violet. Not to mention that a JPG file with red, green, and blue channels cannot represent a true violet, either. So instead a JPG to show violet is recording red and blue of a certain mix, and the display is showing red and blue of a certain mix, and our brain perceives what it is intended to perceive.

 

To be clear, I'm looking for an ink with an actual violet dye. And not an ink with blue and red dyes that make me perceive the same thing. I'm sure this is a niche request with little practical value, but I'm hoping somebody remembers that such an ink was mentioned way back when.

Edited June 12, 2019 by XYZZY

[mke]

Crystal Violet (or Gentian Violet) might fit your wishes.

https://www.abbeycolor.com/stains-and-regents/crystal-violet/

 

Now you need to find an ink made with it.

Start here:

https://www.fountainpennetwork.com/forum/topic/216774-discontinued-herbin-ink/

https://www.fountainpennetwork.com/forum/topic/332583-failed-experiments-starting-with-dye-powders-and-distilled-water/

Edited June 12, 2019 by mke

[white_lotus]

Since ink manufacturers do not reveal the composition of their inks it is difficult to say whether a particular ink is made using a single dye. The common technique of "paper towel chromatography" can show the separation of dyes in a simple way. In looking back through my own ink reviews where I do this, many violet/purple inks were a mixture, and even those that seemed to predominantly be a single dye often had something else added.

 

The following inks appear to be single dye inks. Whether they operate within the spectrum you are looking for is a different matter.

 

J. Herbin Poussière de Lune

Noodler's Violet Vote (2016 LE) (not available any longer)

 

There are many other brands of violet inks, but few reviewers tested the chromatography. But I remember that visvamitra's review often had this, and I know he reviewed many more inks than I (with better pics too).

[Mech-for-i]

Diamine's range of Violet / Purple does give quite a nice match in the form of their Violet or Imperial Purple , but do not trust the screen display, the real ink on paper can look quite different , you might want to try some ink samples

[inkstainedruth]

XYZZY, I'm wondering you can find a Pantone color that matches what you're looking for as a starting point. And then use that to match inks (yeah, I suspect you'll have to buy a lot of samples, or track down that company that was supposedly making custom inks a couple of years ago).

Ruth Morrisson aka inkstainedruth

 

edited for typos

Edited June 12, 2019 by inkstainedruth

[macaddicted]

Does anybody know if there are violet inks that are actually what a physicist would call violet? I.e. with color in wavelength 400 - 450nm?

 

As opposed to purple or red-blue mixes that correspond to violet on a color wheel?

 

Why? Because the trickiness of violet color reproduction in the digital age amuses me.

 

 

Sadist.

 

Your mission, should you decide to accept it, is to purchase a chromatography set and a series of purple and/or violet ink samples and a spectrophotometer able to differentiate the sample's color by light frequency.

 

Should you be killed or captured... Wait. That can't be right. Which Mission force are we doing this recording for?

[macaddicted]

XYZZY, I'm wondering you can find a Pantone color that matches what you're looking for as a starting point. And then use that to match inks (yeah, I suspect you'll have to buy a lot of samples, or track down that company that was supposedly making custom inks a couple of years ago).

Ruth Morrisson aka inkstainedruth

 

edited for typos

 

The thing about PMS guides, at least in the print industry, is that the colors are built up using mixed colors (btw, never ask a pressman to mix a four number PMS color). The OP is asking for an unmixed, pure violet. The sort of color provided by all those dead snails to Roman Emperor's robes.

[WalterC]

There are fluorescent dyes whose emission is in the violet. For example, Alex Fluor 405 is excited by 405nm wavelength light and peak emission is at 421nm.https://www.thermofisher.com/us/en/home/references/molecular-probes-the-handbook/technical-notes-and-product-highlights/the-alexa-fluor-dye-series.html

 

So, a question for you is what light will you be using to look at this ink. Some laundry detergents contain chemical optical brighteners that emit violet light when exposed to ultraviolet (UV). This makes clothes look whiter. These optical brighteners often trigger asthma in people like me.

 

"White paper is treated with fluorescent compounds to help it appear brighter and therefore whiter.Sometimes forgery of historical documents can be detected by placing them under a black light to see whether or not they fluoresce. White paper made post-1950 contains fluorescent chemicals while older paper doesn't. " White paper does not trigger may asthma, fortunately. Things that fluoresce under UV: https://www.thoughtco.com/what-glows-under-a-black-light-607615

[tim77]

Does anybody know if there are violet inks that are actually what a physicist would call violet? I.e. with color in wavelength 400 - 450nm?

 

Do you have a light spectrometer?

[mke]

You have to dissolve inks in Methanol e.g. to see their absorbance spectrum.

 

And you have to dilute them VERY much - 1 / 100000 or more. Otherwise the molecules can interact with each other and you cannot say easily if you see mixtures or single dyes where the molecules are aggregated and then show broad absorption spectra.

 

Here you can see a comparison of ballpen inks - spectrum of crystal violet is also shown:

https://onlinelibrary.wiley.com/doi/pdf/10.1002/jrs.5512

 

Short conclusion: it is not as easy as some people seem to think. You need to understand what and how you are analyzing.

[Bibliophage]

 

The thing about PMS guides, at least in the print industry, is that the colors are built up using mixed colors (btw, never ask a pressman to mix a four number PMS color). The OP is asking for an unmixed, pure violet. The sort of color provided by all those dead snails to Roman Emperor's robes.

Sea snails, specifically, and Tyrian Purple is Purple/blue, depending on if you're talking to a Jewish scholar or a Roman historian (1.4 grams of dye per 12,000 snails? Yeesh. I hope they at least _ate_ the rest of the snail.)

 

Even better - the 'Blue' in Jewish lore, such as King Solomon's robes, was from the snail - but those snails aren't kosher.

[BrassRatt]

XYZZY, we are seriously confusing two different things:

1. single-component, line-like color spectrum (as in your initial posting)

2. single dye in solution rather than several dyes (as in later comments).

 

Each dye acts as a filter, absorbing some of the light passing through. It may be that to get a single narrow band of transmission, the best way is to combine several dyes each blocking part of the spectrum but none of them blocking your 425nm narrow band. That would satisfy your initial quest, but not the other one.

 

It is possible, of course, that some single dye does this well. But regardless, two issues are distinct and should not be confused.

 

Do you have a spectrophotometer, to determine whether Goal 1 is met by something we may suggest? If not, how could you ever know?

[XYZZY]

 

Sadist.

 

Your mission, should you decide to accept it, is to purchase a chromatography set and a series of purple and/or violet ink samples and a spectrophotometer able to differentiate the sample's color by light frequency.

 

Should you be killed or captured... Wait. That can't be right. Which Mission force are we doing this recording for?

Lol. Any hope that I had was based on the wealth of experience here. Probably somebody from FPN has such an ink and is aware of it, and yet perhaps unlikely to see this thread before it falls off the first page. But I can hope :-)

 

"Chromotography set" in this case could be done with a prism. If it's made from red & blue then it will split into that, if it's really violet then it will just come out violet.

 

XYZZY, we are seriously confusing two different things:

1. single-component, line-like color spectrum (as in your initial posting)

2. single dye in solution rather than several dyes (as in later comments).

 

Each dye acts as a filter, absorbing some of the light passing through. It may be that to get a single narrow band of transmission, the best way is to combine several dyes each blocking part of the spectrum but none of them blocking your 425nm narrow band. That would satisfy your initial quest, but not the other one.

 

It is possible, of course, that some single dye does this well. But regardless, two issues are distinct and should not be confused.

 

Do you have a spectrophotometer, to determine whether Goal 1 is met by something we may suggest? If not, how could you ever know?

Ummmm... yes exactly. I'm aware of the difference between additive and subtractive, but you are right that I muddled them in my second post. However, I think the second post still stands, because I was hoping to convey why an RGB display isn't going to illustrate one instead of the other.

 

But you're right re inks: what I'm looking for is an ink that absorbs all except violet, regardless of whether that's done with a single or multiple components.

 

I should have added that I'm not trying to run an expensive physics experiment, if the result isn't a single monochromatic color I wouldn't care. Really I'm just interested in something that would cause some cameras grief and show which cameras do a poor job of recording violet. While my original thought was "paint", that segued to "maybe somebody on InkyThoughts has already figured this out?". Anyhow, I don't think an expensive setup would be required for this specific request: I can trust my eyes for determining whether the light bounced off the page is either violet or purple, and a prism determine show which.

 

But typing "monochromatic" above made me realize a solution that I should have thought of originally. Violet lasers are fairly easy to find.

Edited June 13, 2019 by XYZZY

[Bibliophage]

 

 

But typing "monochromatic" above made me realize a solution that I should have thought of originally. Violet lasers are fairly easy to find.

From personal experience looking, you have to be careful. Many of the violet/UV LED and laser LEDs are all over the place in spectrum wavelength.

[BaronWulfraed]

 

"Chromotography set" in this case could be done with a prism. If it's made from red & blue then it will split into that, if it's really violet then it will just come out violet.

 

 

Prism may not help... dye and pigment as used in ink and paint ABSORB light, and what one sees is the light that reflects off of them (and, in the case of transparent dye, also reflecting off the substrate). Also, while the LIGHT primaries are red, green, and blue, the pigment primaries are yellow, magenta, and cyan.

 

A controllable light source, OTOH, that can be set to produce light only in the desired wavelength might be a better experiment: Red and Blue dye/pigment should look black if illuminated by a pure violet light source (or any light that does not contain blue and red).

[XYZZY]

 

Prism may not help... dye and pigment as used in ink and paint ABSORB light, and what one sees is the light that reflects off of them (and, in the case of transparent dye, also reflecting off the substrate). Also, while the LIGHT primaries are red, green, and blue, the pigment primaries are yellow, magenta, and cyan.

 

 

I don't think it works that way, but I'm not 100%. What I'm thinking is: the light reflecting off a piece of paper is still light and will still be separated by a prism. Bouncing a white light source off a paper coated in cyan ink through a prism will still produce a spectrum, albeit one missing red.

[amberleadavis]

Check out that website you sent me to earlier when discussing Dr. Cantu.

https://www.researchgate.net/

What about this: https://www.researchgate.net/publication/238127843_Chemical_Composition_of_a_Fountain_Pen_Ink . (oops, not the one, but really cool)

[XYZZY]

Check out that website you sent me to earlier when discussing Dr. Cantu.

 

https://www.researchgate.net/

 

What about this: https://www.researchgate.net/publication/238127843_Chemical_Composition_of_a_Fountain_Pen_Ink . (oops, not the one, but really cool)

 

Thanks for that!