Posted on July 9, 2018
Centuries ago, Tyrian purple, a reddish-purple dye made from the fluid of murex shellfish, was the most expensive fabric and paint dye in the world at over $19,000 per pound in today’s currency. This high cost reflected the extreme difficulty of production; it required hunting the specific shellfish species that produced the dye and carefully extracting the tiny amount of purple liquid inside of every shell. It took thousands of shellfish to make a single pound of Tyrian purple and the color was so rare and expensive that it became a status symbol for royalty and the ultra-wealthy at the time.1 For hundreds of years, purple was seen as a royal color, a tradition that continues even today, all because of Tyrian purple’s almost prohibitively expensive manufacturing process.
Today, purple dye is much more common than it once was. Modern textile and paint manufacturers have relatively inexpensive synthetic sources for purple, such as Mauveine, made artificially from coal tar.2However, although the invention of a wider range of synthetic dyes has made dyed products easier to manufacture than ever before, there are still a number of commercial dyes used today that remain rare or very difficult to make.
When manufacturers choose to use these uncommon, expensive dyes in their products, however, they face a major challenge: they need to test their dyes and products for color consistency, but they also want to avoid wasting product during the testing phase. In order to solve this problem, manufacturers can use spectrophotometers that are capable of testing very small sample sizes. By shrinking the size of their test samples, manufacturers of expensive or rare dyes can thoroughly test their products for color consistency while also keeping their overhead costs as low as possible and preserving scarce materials.
The Challenges of Manufacturing Rare or Expensive Dyes
The color consistency of a product can significantly impact quality perception, which is why every manufacturer that works with dyes needs to implement strict, spectrophotometer-based color quality control protocols throughout the manufacturing process. Industries that work with inexpensive commercial dyes are able to perform these color quality control tasks fairly easily. For instance, many hair dyes are made with relatively inexpensive raw dye materials, including amino compounds which are plentiful and readily available for commercial use.3 Hair dye companies can test all of their dyes for color consistency using a spectrophotometer with a standard sample size port. These companies don’t necessarily have to worry about the size of the instrument’s required minimum sample because the dyes they use are plentiful and easy to produce in mass quantities.
However, industries that choose to make products out of rarer or more expensive dyes will likely have to adjust their color quality control testing in order to avoid wasting resources. In general, dyes derived from natural materials are more expensive than those made synthetically. This is because natural dyes contain less than 2 percent color, on average, compared to synthetic dyes, which contain more than 90 percent color. This means that you need far more natural material to create the same amount of color you can get from synthetic dyes, significantly driving up the cost of the natural dyes. In fact, the most expensive dyes in the world, such as lapis lazuli and brazilwood, are naturally derived.4 To test the color of rare or expensive dyes like these without wasting more product than absolutely necessary, it is essential to use a spectrophotometer equipped with accessories designed specifically for smaller-than-average sample sizes.
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