Natural Dyes - Colour Fastness

It has been more than two months since my natural dye experiments during the art residency at L'Observatoire. I decided to take a break (it was Christmas and New Year) before going into it again, but during this gap I had to do a few tests to determine the colour fastness of the dyes.

So far my tests include:

1. Mango leaves, Mangifera indica. L. - yellow green
2. Rukum masam, Flacourtia inermis Roxb - muted pink
3. Eucalyptus leaves (immersive and eco print) and bark, Eucalyptus camaldulensis Dehnh - rich brown
4. Golden shower tree pods, Cassia fistula - pale brown
5. Yellow onion skins - deep orange
6. Red onion skins - pale orange
7. Coffee grounds - very pale brown
8. Avocado seeds and skins - tones of pink
9. Blue pea flower, clitoria ternatea - blue
10. Dragon fruit - pale pink

Colour fastness is the ability of the dyed material to resist fading due to light or water.  To test for light, I covered half of the swatch with foil, leaving the other half exposed. For the water fastness, I sewed individual swatches onto white cotton fabric and laundered the swatches in the washing machine.  In fact, I washed them in the same manner as I would normally do with my clothes.  The objective is to see whether the colours would fade, run or even transfer onto other clothing. 

Colour fastness to light.

The colour chart comprised screen printed natural dyes (the squares), and swatches of dyed fabric covered in half with foil. The chart was exposed to indirect light from 4 November - 9 January 2018.

Observations:

• Screenprinted swatches 

1. fading observed for tumeric, eucalyptus leaves, blue pea, dragon fruit.
2. colour change from pink to brown for rukum masam

• Immersed swatches

1. fading observed for dragon fruit and blue pea

Images below, before (L) and after (R). 

Colour fastness to water

After 4 rounds of washing the swatches in the washing machine (with drying in between), I opened up the fabric to see the result.

There was transfer of colour from the dyed swatch from the yellow onion skins (acidic) and tumeric. I was pleasantly surprised that the rukum masam did not wash off.

Note:  I wish I had done this better and used my knowledge in science - always have a control rather than rely on photographs. As you can see, the lighting was not ideal.