Turpentine and white spirit have been the default solvents for oil painters for generations — effective, yes, but also flammable, toxic, and unpleasant to work with in any space that isn't extremely well ventilated. Zest-it is the alternative that a growing number of oil painters have quietly switched to and never looked back from. Made in the UK using the zest of citrus fruits as its active ingredient, it does everything turpentine and white spirit do — thinning paint, cleaning brushes, removing oil-based media from tools and surfaces — with none of the associated hazards and with a genuinely pleasant orangey citrus smell instead.
Zest-it is non-toxic, non-flammable, biodegradable, and carries no hazard classification — which makes it suitable for use in home studios, shared spaces, and teaching environments where conventional solvents are impractical or undesirable. Despite being free from the harsh chemicals of traditional solvents, it is a high-strength diluent that requires only a small amount to thin paint effectively, and it evaporates without leaving any oily or waxy residue on the canvas or paper.
For brush cleaning it is particularly effective — it removes fresh oil paint from all brush types including sable, sable mix, synthetic, and bristle, and can even remove dried paint with a little patience. One of its most practical qualities is that it is reusable: pour the used diluent into a jar, allow the paint sediment to settle out, decant the clear liquid off the top, and it is ready to use again. A single 250ml bottle therefore goes considerably further than a comparable volume of turpentine or white spirit would.
Beyond the studio, Zest-it can also be used around the home to remove oil, grease, tar, soot, and wax from surfaces — a useful additional quality that makes it a versatile household product as well as an artists' material.
It is compatible with oil paint, oil pastels, oil paint sticks, wax-based media, and oil-based inks. It is not suitable for use with water-mixable oils, acrylics, or other water-based media.
What is Zest-it made from? The active ingredient is citrus zest — derived from the peel of citrus fruits. This gives it both its cleaning and thinning properties and its characteristic pleasant orangey smell. It is non-toxic, non-flammable, and biodegradable.
Can it be used as a painting medium as well as a brush cleaner? Yes. It works as a diluent for thinning oil paint — particularly useful for the first lean layer, grisaille work, or underpainting, where thinning the paint without adding oil is important. It evaporates without leaving any residue, making it suitable for lean underlayers in traditional fat-over-lean technique.
Is it reusable? Yes. Allow used diluent to settle in a jar until the paint sediment sinks to the bottom, then carefully decant the clear liquid and reuse it. This makes a 250ml bottle last considerably longer than a comparable volume of turpentine or white spirit.
What brushes can it be used with? All oil painting brush types — sable, sable mix, synthetic, and hog bristle. It cleans without drying out the bristles, which is a common complaint with harsher solvents. It can remove both fresh and dried oil paint.
Is it safe to use indoors? Yes. Zest-it is non-toxic, non-flammable, and carries no hazard classification, making it suitable for home studios and enclosed spaces where conventional solvents would require significant ventilation. As with all art materials, reasonable airflow is always sensible, but it does not present the fume or fire risk associated with turpentine or white spirit.
What media is it compatible with? Oil paint, oil pastels, oil paint sticks, oil bars, wax-based media, and oil-based inks. It is not suitable for water-mixable oil paints, acrylics, or water-based media.
