New Worlds: Pigments and Dyes

Jul. 4th, 2025 06:00 am
[syndicated profile] bvc_feed

Posted by Marie Brennan

Austere cathedrals and classical busts in white stone; movie peasants in layered rags of brown. Despite what you’ve seen, the people of the past loved color as much as we do. They painted their churches and their statues, they dyed their clothes, and while it’s true they faced greater limitations in their color choices and availability than we do, they still made use of what they had.

One of those limitations, of course, was money. Some pigments and dyes can only be made from sources available in one region; for quite some time, the only truly vivid blue paint in Europe was ultramarine, made from ground lapis lazuli, which had to be imported from Afghanistan. (The secret of creating Egyptian blue, calcium copper silicate, had been lost.) Others are expensive because of the effort involved in their creation; harvesting saffron is a labor-intensive process to this day, and so even in its native range, heavily saffron-dyed clothing was usually an elite textile. Others combine both of those factors: Tyrian purple has to be extracted from particular species of sea snails found only in certain parts of the eastern Mediterranean, and you need massive quantities, with one historian estimating twelve thousand snails required to produce enough dye for the trim of a single garment.

These factors are familiar to many people, but others may be less so. In fabric dyeing, for example, the first batch of cloth added to the vat will absorb the most intense, saturated color. Subsequent batches will have progressively more washed-out shades. The strong colors were therefore often the most prestigious and expensive. You also have to consider color fastness, i.e. the resistance of a pigment or dye to fading in light, washing out in the laundry, or rubbing off on the skin. (Probably quite a few of us here still have the experience of noticing the spine of a book becoming more faded than its cover, due to greater exposure to the light.) Fastness in dyes is achieved partly through the use of “mordants” that will help bind the color, but some options are more color fast to begin with — and, naturally, those will be more desirable and probably more expensive.

With pigments, you also have to consider the chemical behavior of the paint. Quite a lot of chemistry goes into figuring out how to make certain colors; unfortunately for painters, many of whom used to make their own pigments, quite a lot of those chemicals were horribly toxic. (They also stank: both dyeworks and artists’ studios tended to be fairly rank places, and even the paintings themselves could be unpleasantly odiferous.) But in addition to poisoning themselves with lead and mercury and other inimical substances, painters had to plan for how their pigments would react with each other. The composition of a work wasn’t just a question of form and perspective and other such concerns; they had to plot out their colors to make sure adjacent pigments wouldn’t form a chemical reaction that discolored or destroyed them both.

TV and movies also tend to make us forget that the palette of available colors was restricted to what you could get from plants, minerals, and other natural substances. While some truly vivid colors were possible, many of them were softer, more muted. The TV show of The Wheel of Time did a good job of showing this: the rural people of the Two Rivers don’t all wear brown, but neither do their clothes display a lot of intense, saturated shades. Getting past these limitations required more chemistry . . . and this is when we started killing people with wallpaper.

Scheele’s Green is a compound invented in the late eighteenth century and used both as a paint and as a textile dye. It was hugely popular in the nineteenth century because it was more brilliant and more durable than previous green pigments; people used it for everything from decoration to candles to children’s toys to food dye. It also happens to be a cupric hydrogen arsenite — yes, arsenic. Even if you didn’t put it in your food, you wound up eating it anyway, because things like wallpaper continually shed arsenic dust into the air, contaminating everything around them. That’s a notorious example, but hardly the only onet: the nineteenth century saw a huge boom in the development of synthetic aniline and azo dyes, many of which were profoundly unsafe by modern standards. But they also let people adorn their homes and themselves with colors that were previously impossible, and so in an era when many hazards weren’t yet understood, fashion trampled safety flat.

These days we have regulations saying you can’t paint your home with lead white or other environmental hazards, and we’ve developed safer alternatives. Looking at what’s available in your local paint store, you’d be forgiven for thinking we’re done: we’ve developed pigments for all the colors, and there’s nothing left to invent.

For the layperson, that’s effectively true. But talk to a painter, and you’ll find out that there are still chromatic horizons to be conquered. Vantablack made news about a decade ago for being one of the darkest blacks in existence, absorbing more than 99.9% of visible light. It also made news for the controversy over sculptor Anish Kapoor securing an exclusive license for one form of Vantablack; only his studio is permitted to use it. The artist Stuart Semple retaliated by creating a “pinkest pink” pigment and licensing it to everyone in the world but Kapoor. We’re still developing the ability to produce new colors, and who knows where that could go in the future.

Especially since this wanders in the direction of weird tricks with optics and perception. There’s a whole category referred to as “impossible colors,” which are hues we’re not capable of perceiving under normal conditions. You can apparently achieve some of these by staring for a long time at a block of one color, until your cone cells become fatigued, then shifting to another; if you stare long enough at bright yellow and then at black, you will see stygian blue, which is as dark as black while also being blue. There are may also be colors outside the spectrum human eyes can perceive, though I’ve seen it questioned whether creatures like mantis shrimp actually see different colors than we do.

That uncertainty hasn’t stopped fiction writers! H.P. Lovecraft’s “colour out of space,” Terry Pratchett’s “octarine,” the seven colors of the “Neathbow” in Fallen London and its related games . . . these are generally used as markers of alienness, magic, or both. Sometimes they have special properties; sometimes they’re literally just decorative elements to make the setting seem more unusual, to extend it beyond the ordinary limits of human perception.

To fully explore this topic would require much more knowledge of color theory, chemistry, and physics than I possess. But if you find it interesting, I eagerly await your novel about someone attempting to develop a magical pigment for an impossible color!

The Patreon logo with the text "This post is brought to you by my imaginative backers at Patreon. To join their ranks, click here!"

[syndicated profile] tim_harford_feed

Posted by Tim Harford

A radical thought experiment transforms the lives of a new breed of philanthropists, as they follow the logic of altruism to extraordinary lengths. The most famous convert to the Effective Altruism movement, Sam Bankman-Fried, is either a humanitarian hero, or a con artist at an astonishing scale, or most bafflingly, both.   

[Apple] [Spotify] [Stitcher]

Further reading

The definitive account of Sam Bankman-Fried’s astonishing career arc is Michael Lewis’s book Going Infinite: The Rise and Fall of a New Tycoon. This episode also relied on sources including Gideon Lewis-Kraus’s profile of Will MacAskill in The New Yorker, The Reluctant Prophet of Effective Altruism, and contemporary reporting in outlets including Rolling StoneVox, the BBC and CNBC. Will MacAskill’s book is called What We Owe The Future, and Peter Singer’s essay is Famine, Affluence and Morality

[syndicated profile] gizmag_newatlas_feed

Posted by Mike Hanlon

It's just a piece of rock, but it's from another planet, which makes it incredibly valuable. Bidding sits at US$1.98 million (inc BP) with two weeks to go before the hammer falls

If rocks could talk, this one (NWA 16788) would have a great tale to tell. It was ejected from its own planet by a massive asteroid collision, wandered around in space for ages, then eventually found its way into the gravitational field of Earth and landed 140 million miles from where it started, being found in 2023.

Continue Reading

Category: Collectibles, Lifestyle

Tags: , , ,

(no subject)

Jul. 4th, 2025 04:48 am
[syndicated profile] apod_feed

If you know where to look, you can see a thermonuclear explosion from a white dwarf star. If you know where to look, you can see a thermonuclear explosion from a white dwarf star.


[syndicated profile] icanhascheezburger_feed

Posted by Etai Eshet

Some neighborhoods treat pets like local celebrities, but there's always someone ready to play talent agent and book them for a private tour. 

In these circles, the idea of ownership is little more than a technicality, and any animal with a taste for adventure is at risk of being "adopted" by the boldest opportunist on the block. Here, the property line is just a suggestion, and the only thing more flexible than a cat's spine is a neighbor's sense of entitlement.

melanism

Jul. 4th, 2025 04:35 am
[syndicated profile] wordsmithdaily_feed
noun: An inherited overproduction of melanin leading to unusually dark coloration.
[syndicated profile] gizmag_newatlas_feed

Posted by Bronwyn Thompson

Scientists have developed a new antibody treatment that blocks pollen at the point of entry

Scientists have developed a nasal "molecular shield" that disarms pollen, blocking allergic reactions fast without the use of drugs. This non-invasive method to effectively silence hay fever could be a game changer for the roughly 81 million Americans currently in a lifelong battle with airborne allergens.

Continue Reading

Category: Allergies, Illnesses and conditions, Body & Mind

Tags: , , , , , ,

[syndicated profile] gizmag_newatlas_feed

Posted by Paul McClure

[Error: Irreparable invalid markup ('<img [...] creativity">') in entry. Owner must fix manually. Raw contents below.]

<p class='syndicationauthor'>Posted by Paul McClure</p><p class="ljsyndicationlink"><a href="https://newatlas.com/medical/internet-access-creativity-fixation-effect/">https://newatlas.com/medical/internet-access-creativity-fixation-effect/</a></p><p><img src="https://assets.newatlas.com/dims4/default/11ff512/2147483647/strip/true/crop/2000x1125+0+0/resize/1440x810!/format/webp/quality/90/?url=https%3A%2F%2Fnewatlas-brightspot.s3.amazonaws.com%2Fab%2Fe6%2F098dd0d94bb9ba6a99964bcf2de7%2Fdepositphotos-49536991-l.jpg" srcset="https://assets.newatlas.com/dims4/default/ed968d3/2147483647/strip/true/crop/2000x1125+0+0/resize/440x248!/format/webp/quality/90/?url=https%3A%2F%2Fnewatlas-brightspot.s3.amazonaws.com%2Fab%2Fe6%2F098dd0d94bb9ba6a99964bcf2de7%2Fdepositphotos-49536991-l.jpg 440w,https://assets.newatlas.com/dims4/default/1141351/2147483647/strip/true/crop/2000x1125+0+0/resize/725x408!/format/webp/quality/90/?url=https%3A%2F%2Fnewatlas-brightspot.s3.amazonaws.com%2Fab%2Fe6%2F098dd0d94bb9ba6a99964bcf2de7%2Fdepositphotos-49536991-l.jpg 725w,https://assets.newatlas.com/dims4/default/f0d2ab1/2147483647/strip/true/crop/2000x1125+0+0/resize/800x450!/format/webp/quality/90/?url=https%3A%2F%2Fnewatlas-brightspot.s3.amazonaws.com%2Fab%2Fe6%2F098dd0d94bb9ba6a99964bcf2de7%2Fdepositphotos-49536991-l.jpg 800w,https://assets.newatlas.com/dims4/default/b343a32/2147483647/strip/true/crop/2000x1125+0+0/resize/1200x675!/format/webp/quality/90/?url=https%3A%2F%2Fnewatlas-brightspot.s3.amazonaws.com%2Fab%2Fe6%2F098dd0d94bb9ba6a99964bcf2de7%2Fdepositphotos-49536991-l.jpg 1200w,https://assets.newatlas.com/dims4/default/d0ad506/2147483647/strip/true/crop/2000x1125+0+0/resize/1920x1080!/format/webp/quality/90/?url=https%3A%2F%2Fnewatlas-brightspot.s3.amazonaws.com%2Fab%2Fe6%2F098dd0d94bb9ba6a99964bcf2de7%2Fdepositphotos-49536991-l.jpg 1920w" alt="Depending on how it's used, internet access - or "Googling" - can hinder creativity" /><p>Using Google might spark your creativity, or it might stifle it, but this depends on the circumstances, according to a new study. We know the internet isn’t going anywhere, but we may need to hold on to our humanity to use technology more effectively.</p><p><a href="https://newatlas.com/medical/internet-access-creativity-fixation-effect/">Continue Reading</a></p><p><b>Category:</b> <a href="https://newatlas.com/medical/">Body &amp; Mind</a></p><p><b>Tags:</b> <a href="https://newatlas.com/tag/internet/" rel="tag">Internet</a>, <a href="https://newatlas.com/tag/creative/" rel="tag">Creative</a>, <a href="https://newatlas.com/tag/thinking/" rel="tag">Thinking</a>, <a href="https://newatlas.com/tag/carnegie-mellon/" rel="tag">Carnegie Mellon University</a></p><p class="ljsyndicationlink"><a href="https://newatlas.com/medical/internet-access-creativity-fixation-effect/">https://newatlas.com/medical/internet-access-creativity-fixation-effect/</a></p>
[syndicated profile] file770_feed

Posted by Mike Glyer

(1) AUTHORS CALL ON BIG FIVE PUBLISHERS NOT TO USE AI. In an open letter released June 27 “Authors petition publishers to curtail their use of AI” – NPR has the story. Sff is well represented among the initial signers … Continue reading
[syndicated profile] icanhascheezburger_feed

Posted by Lana DeGaetano

Feeling pawtriotic? Nothing makes pawrents more excited for a howliday more than cat memes that can be applied to just about any situation that's ever existed. How do I know this? Well, you're here, aren't you?

Whether you celebrate the Fourth of July in the U.S. or couldn't care less about the holiday, the point here is that freedom makes you feel powerful. What else is powerful? Our felines—it's their main character trait. All they know how to do is boss their pawrents around, repeatedly and continually, because they know we will fulfill their every request. There's nothing quite like a meowther's love…

I'm feeling extra pawtriotic about cat country right about now. Patriotism is devotion, it is love, it is fear… and this is how it feels to be the owner of a cat who runs the household. Though we can always give them a half-scoop of food instead of a full one, or skip out on the nightly Churu, we never do. Why? Well, that wouldn't be any fun! Our cats enjoy bossing us around, and we hoomans live to serve. Scroll below to get your much-needed dose of the most independent animals on earth.

Your inbox deserves hissterical cat content. We deliver. Weekly. Subscribe here.

What’s math for anyway

Jul. 4th, 2025 01:44 am
[syndicated profile] yarn_harlot_feed

Posted by Stephanie Pearl-McPhee

Well, spoiler alert… Ranunculus fits just fine. This was not at all a guarantee, despite the rather ridiculous number of times that I checked before binding off and going back to do the neck. I felt compelled to pop back and tell you all how it was fitting, not just because I mentioned that I was worried it was going to be too short, but because the very last picture I posted of it on instagram looked like this.

Let’s back up to how I got there – which I admit was a very dramatic moment – one where I went to pull a finished sweater over my head and lo, it did not go. On the upside, I did stop worrying about the length for a while. Here’s what happened. I told you all in the last post that since I changed the gauge on this sweater (I went down a needle size or so to make a fabric I like better. What the heck, it’s my sweater.) That meant though, that I wasn’t at all sure how many I wanted to cast on for a top down sweater, so I skipped it. I cast on provisionally after the neck, and just started working the sweater. When I was done, I came back, picked up all the stitches, and worked the neckband.

Here’s the thing though. Did I do any figuring? Did I follow up on my original thought and have a little chat with my inner knitter about how I was worried it would be too small because I went down a needle size, and perhaps reflect upon how none of that had changed? Yeah verily, did I look upon the knitting and think “Well Stephanie, this is exactly the moment one knits a swatch for” and having though that, picked up the swatch that I did indeed knit, and count how many stitches it would take to go around my noggin? Did I?

No, gentle knitter, I did not. Even though the swatch sat nearby, even though (sort of unbelievably) I had a tape measure nearby… nope. I just took a look at that neckline and decided to just smash the question with the weight of my experience and thought “Looks right.” and just went for it. It was not right. (See above.)

Anyway, obviously I ripped back the cast on, and all the ribbing, and then I did the math and NOW this sweater both goes over my head and …

It is the right length. I knew it.

Sweater: Ranunculus, Yarn; (Cottage Fingering, 50% Merino, 20% Linen, 15% Silk, 15% Cotton) Modifications, changed the gauge, provisional neckline, fewer stitches for the neckband itself – oh, and I only did the short rows in the back, and I made them wider. It fits me better that way.

For now, I’m off to bed. Jen and I are going on a training ride in the morning, and I have to get up at 5:30am to make it happen, and that is not a thing that is really in my wheelhouse without getting to bed early. If I survive, I’ll pop back and tell you a story about some socks.

(PS. If you wanted to sponsor me or Jen tomorrow to encourage two rather old soft women to ride like the wind, you can do it by clicking on our names. We start to ride at 7, and can use whatever encouragement you can offer. )

Stephanie

Jen

[syndicated profile] languagelog_feed

Posted by Victor Mair

We've met Julesy before:  "The conundrum of singing with tones" (5/30/25).  She has a Ph.D. in linguistics and knows how to communicate her scientific knowledge of Mandarin to intelligent laypersons.  Here she is again, this time telling us some very important things about the differences between words and characters:

During the first half of her presentation, Julesy made me feel that she was preaching the gospel according to VHM (difference between zì 字 ["character"] and cí 詞 ["word"]), spacing / parsing, etc., but in the second half she got into some statistical surveys and the notion of "collocations" that were "lexically significant", and salvaged some unique properties of sinographs while yet assimilating them into modern concepts of linguistics.

What a breath of fresh air to have someone with her expertise and exactitude explaining how Sinitic languages work.  Until the recent past, most of what was purveyed about "Chinese" was either too technical and theoretical for the non-specialist to grasp or was a mishmash of nonsense gobbledygook.

Keep 'em comin', Julesy!

 

Selected readings

 

[syndicated profile] snopes_feed

Posted by Cindy Shan

Social media videos being shared in late June 2025 claimed that health authorities linked the popular spicy snacks to child deaths.

Profile

muninnhuginn: (Default)
muninnhuginn

June 2025

S M T W T F S
1 234567
891011121314
15161718192021
22232425262728
2930     

Most Popular Tags

Style Credit

Expand Cut Tags

No cut tags
Page generated Jul. 4th, 2025 06:16 am
Powered by Dreamwidth Studios