Blending oil and water

Santanu Chakraborty | Updated on December 20, 2019 Published on December 20, 2019

Stark contrast: Oil paints not only give the richest colour but also deep shades of black and bright whites, as seen in Rembrandt’s The Night Watch   -  IMAGE COURTESY: WIKIMEDIA

Artists have struggled to blend elements that are disparate, but make vivacious colours

Oil and water don’t mix, it is said. They haven’t for millennia, perhaps, hundreds, if not, thousands of millennia. Hence, it is assumed that they never will. However, new developments in science are breaking this age-old notion about oil and water.

But let us first take into account methods of painting that would be considered traditional today, but are actually tried and tested by the rigours of time. To paint, one needs at least three things — brush, paint and a material on which to apply paint. Paper, wooden panels or walls are the commonly used surfaces and paints are used either straight from a tube or diluted with some medium. Dilution of paint with a fluid medium — typically water or oil — is an important process, and results in different shades of the same hue instead of just one. Yet, blending disparate elements is a difficult task, one which artists have pondered over for ever.

Water mixable paints — water colours for short — produce thin and luminous layers of paint over paper. The medium is not just convenient, but produces effects of such delicacy that artists across cultures have used it to create masterpieces of great subtlety.

Water colours dry quickly and are nearly impossible to retouch with control; this, combined with their unpredictability when applied onto wet paper, has produced an approach to painting that is spontaneous and unmatchable. Water-based paints, however, are fragile and are near impossible to restore.

Oil mixable paints, typically made by grinding pigments with oils such as those from linseed or safflower, assure a certain surface sheen and better colour strength since oil can hold a large amount of pigment. However, the greatest strength of oil paint is also its Achilles heel. An oil painting takes forever to dry. But on the other hand, it allows the artist the freedom to work on a single layer of paint till the desired effect is achieved. The paint can be used in thick, full-bodied, deeply pigmented layers to give not only rich colour but also deep blacks and bright luminous whites.

Nevertheless, oil paints have their unique issues. The pungency of linseed oil can trigger headaches and allergies. The volatile solvents used to clean oil paint brushes and palettes are truly toxic for humans, not to mention the harmful impact on the environment.

Efforts have been made to produce deep, thick, opaque water-based paints. Methods to apply oil paints in thin delicate layers have been explored to great effect as well. Yet both these styles of painting, with their unique optical properties, use materials that have unique advantages but don’t play well together. Water and oil do not mix. So there is clearly no chance that we may combine the best properties of both for a new future in painting.

But that may be set to change. Scientists are demonstrating that with imagination, tenacity and technique, it is indeed possible to mix two disparate components. Let me begin with the simplest iteration of the issue at hand. We want to mix paints with oil for the longevity and lusciousness it guarantees to a work of art, but also be able to both clean and dilute this paint with water as well as oils and other solvents.

It might appear a difficult ask, even a pipe dream. But it is not impossible. Let me begin by drawing attention to our day-to-day world where material interactions which are seemingly unusual happen almost every day. All we must do is look. We fry foods with oil but wash those very vessels with water. Since water does does not dissolve oil one often uses a third product — soap. Soap or detergents are an intermediary whose function is to have a particular molecular shape, one end of which can bind water, while the other binds oil. This results in the formation of a giant matrix where two elements, usually antagonistic, can come together in the presence of a third particle. Such agents exist in many contexts, I will call them emulsifiers. Addition of these into non-water soluble paints can make them soluble in water, albeit with some effort.

What if we learned some aspects of the emulsifier molecule — the oil molecule — and made it our own? Could we modify an end of the oil molecule so that it would have a mild affinity for water molecules without repelling those of its own kind? Turns out scientists have successfully made these modifications and a new class of oil paints has emerged which can be cleaned with as well as diluted by water. Why did scientists consider modifying the oil molecule instead of water? Turns out that oil is a large composite molecule which offers many possibilities of rearrangement without changing its essence. Water, on the other hand, is a tiny molecule composed of just two kinds of atoms, and that makes it hard to edit without serious consequences.

While science has made possible ideas previously thought impossible, nature too has shown that there is still much to learn from it. All one needs is a dash of colour to fire up the imagination.


Santanu Chakraborty is a Bengaluru-based engineer, scientist and photographer

Published on December 20, 2019
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