Colour systems have been established in order to allow artists and designers to study colours, as well as to communicate colour choices with other designers and manufacturers, retailers and customers.
“By entering smart colours, such as thermochromic colours, into the textile and fashion design world, existing colour systems and their terminologies are not sufficient for describing the expressions achieved during a design process involving thermochromic colours, as they cannot display the behaviour in relation to other static textile pigment pastes and varying temperatures”, says Marjan Kooroshnia, Senior Lecturer in textile design at the Swedish School of Textiles.
In her PhD thesis, Marjan Kooroshnia highlighted the need of a new thermochromic colour system.
“The significance of this colour system, for textile and fashion design in both academy and industry, is related to facilitate communication between designers and manufacturers, retailers and customers regarding, understanding of, and design with thermochromic colours”, she says.
During the latter stages of her PhD research process, she did a few attempts to create a thermochromic colour system. The latest version is based on a pyramid with a triangle base of fully saturated colour.
“It seems that it has potential for development and proposing the first thermochromic colour system“.
Created methods for diverse colour changing effects
Thermochromic inks are colouring agents characterised by their ability, when printed on textiles, to change colour in response to temperature fluctuations. Below their activation temperature they are coloured, and above their activation temperature they are clear or have a light hue. They are usually blended with static pigments, allowing them to change from one colour to another.
In her Phd thesis (2017), Marjan Kooroshnia, proposed different methods to create diverse colour changing effects on textiles.
“In one of the methods, I mix thermochromic inks with static pigments and print the colour mixtures in layers on top of each other. In this way, I can create more complex dynamic patterns on textiles, in which the colour of the pattern changes from one colour, possibly, with different nuances to multiple vibrant colours”, she says.
In addition, she developed two pedagogical tools for teaching the behaviour of thermochromic inks. One is based on printed colour swatches that demonstrate the colour transitions of thermochromic inks at different temperatures, and tasks, which create opportunities for students to learn the principles of colour transition by actually experiencing them. Another one is called thermochromic colour transition sample spectra and can be used as guidelines for studying and teaching thermochromic inks.
To spread her unique knowledge about thermochromic inks, Marjan Kooroshnia has been invited to many different universities to run a thermochromic workshop. In addition, she has been invited to have an exhibition at different places to display a wide range of aesthetic possibilities offered by thermochromic inks on textiles. Recently, three of her thermochromic prints has been shown at Material Xperience exhibition in Rotterdam Ahoy, Netherlands, and some has been shown at Ikea Museum in Älmhult.
“Recently, I have been invited to teach at The Academy of Fine Arts in Warsaw in Poland, and at Vilnius Academy of Arts in Lithuania. I also run the thermochromic workshop at The University of Auckland in New Zealand, at Aalto University in Finland, and Bergen Academy of Art and Design in Norway”, she says. She runs the thermochromic workshop three times a year at the Swedish School of Textiles, University of Borås.
Facts about thermochromic inks
There are two major types of thermochromic inks: liquid crystal and leuco dyes. Marjan Kooroshnia works with leuco dye-based thermochromic inks.
The future potential of thermochromic colours is not limited to textile and fashion design. Other fields for potential utilization are healthcare in hospital and home environments, safety applications for various professions, monitoring procedures etc.
The thermochromic inks have a limited lifespan, when compared to traditional dyes. However, it seems that this creates barriers to more creative design, it may, in turn, lead to their use in a more creative way. For instance, colour-changing of a shower curtain printed with thermochromic inks stops after e.g. 3000 times being exposed to hot water. When the colour changing stops, it is a signal for the user that it is time to change the curtain, as mold starts to grow on the shower curtains after that.
About Marjan Korooshnia