Both “hydro” coming from Greek origins for water and “hygro” coming from the Greek “hygrós” for wet or moist, tend to be used in two terms for the same optical phenomena.
ASTM E284 on standard appearance terminology prefers the name “hygrochromic”.
Hydrochromic or hygrochromic is a descriptor for optically active samples that change color with moisture content, most often inks, dyes and coatings.
Perhaps a distinction between these terms can best be thought of as related to the volume of water.
In extreme cases of hydrochromism, with the addition of water in quantity, the sample color can change from one color to another . In these cases color measurement can be used to verify lot-to-lot consistency in the extremes of the color shift.
In more subtle cases of hygrochromism with textile samples as an example, a change in relative humidity can cause a predictable change or bias in measured color values. In these more subtle cases, a conditioning cabinet can be used to standardize or condition the moisture content of the material.
FAQ: “How can we help you? Good afternoon, We are interested in Hygrochromic inks or master batch, because we manufacture moisture absorbers and we are very interested in apply this inks into our products.”
We list hydrochromism or hygrochromism in the MeasureTrueColor blog as a sample variable to be controlled when measuring the color of some absorbent samples such as dyed textile colors. In this case, it is the textile substrate that absorbs moisture more than the dye and sample conditioning prior to color measurement is the standard technique used to address it.
Other optically active sample characteristics that can effect color measurement include UV optical brightening, translucency, light trapping, photochromism and thermochromism.
HunterLab is a manufacturer of color measurement instruments, and not an ink or colorant manufacturer. So, we are unable to help you in terms of encapsulating moisture absorbers into inks. Our suggestion in looking for markets for your moisture absorbers would be to contact all the ink manufacturers in your region and find out if moisture is a problem in their products.
Mr. Philips has spent the last 30 years in product development and management, technical sales, marketing, and business development in several industries. Today, he is the global market development manager for HunterLab, focused on understanding customer needs, providing appropriate solutions and education, and helping to solve customer color challenges across these industries and cultures.LinkedIn