Hellooo all,
This post is inspired by a recent observation at a fruit stall along Bugis street. It is that time of the year again when trays of mangosteens and durians can be seen (and smelled)! This sharing takes us back to the first mangosteen ink we made back in 2022 with mangosteen shells:
While picking mangosteens, I often notice that quite a few of them exude a bright yellow sap which looks gummy but is hard to the touch. This yellow exudate appears at all parts of the fruit, especially at the end of fruit stems -
or at times forming long streaks like this.
This yellow sap is called gamboge, a latex present in plants from the Garcinia group. Mangosteens belong to this group of plants, and like other parts of the tree, the fruits produce this yellow latex. There were times when we opened up mangosteen fruits to find the flesh tinted yellow instead of the expected white creamy colour. This discoloration means that the latex has seeped into the flesh, turning the taste into an unpleasant bitter one.
But this yellow latex is also desirable in a different context.
Gamboge latex from Garcinia trees has a long history as a vibrant yellow dye and ink, with its use dating back to the eighth century. Though mangosteen gamboge is not the preferred source by artists, we thought it would still be interesting to explore its qualities for ourselves through making it.
The gamboge dissolves readily in warm water. While mulling it in the small glass pestle and mortar, it sticks onto the surfaces quite stubbornly, leaving a layer of cracked yellow residue on the surface.
There is a fascinating book “Chromatopia” by David Coles which wrote on the harvest of gamboge from Garcinia trees. A bamboo tube is placed under an incision made on the trunk until the latex fills it up, similar to how rubber is collected. This latex is then dried and hardened into brownish-yellow cylinders which can then be grinded down into bright yellow colour pigments. The name "gamboge” stems from the old name of Cambodia, “Camboja”, where the tree was especially cultivated for gamboge trade.
Perhaps due to its transparency, the gamboge yellow is mixed with blues to achieve different shades of green. The artists behind the Ajanta mural paintings in Kerala, South India, are said to combine it with indigo powder to get different shades of green (Nayar et al., 1999). The paint ‘Hooker’s Green' is a mix of gamboge and Prussian blue or Green Malachite (Winter et al., 1997) for a deeper shade of green that is suitable for painting leaves.
We tried blending these colours for ourselves with differing ratios of indigo paint -
Gamboge by itself is a transparent yellow, but when mixed with a more opaque indigo it lends a deeper, luscious shade. As gamboge itself is sappy and sticky, a binder did not feel necessary.
Would you try making this yourself when you see some mangosteens? If you have some thoughts and ideas, would be lovely to hear in the comments :)
Upcoming event!!!
We are hosting a masak-masak session at our studio on 14 September. Link to register for this upcoming session is here! This will be our fifth masak session and we will be exploring hapa zome with members.
For deeper learning with a group of people also interested in working with natural colours and plants, do upgrade to paid membership in our study club through Substack for $15-16/month, and get access to other benefits as well.
Thank you for reading till the end! We appreciate your help to let friends who may enjoy such sharings know about our newsletter as well!
Till next letter,
Liz and Shirin
References:
Nayar, T. S., Binu, S., & Pushpangadan, P. (1999). Uses of plants and plant products in traditional Indian mural paintings. Economic Botany, 53(1), 41–50. https://doi.org/10.1007/BF02860791.
Winter J. (1997). Gamboge in Fitzhugh EW (Ed.) Artists pigments a handbook of their history and characteristics. Vol. 3. Oxford University Press, Washington.