Paints and varnishes are colourants based on plastic dispersions. They can often be diluted with water an harden to form a waterproof coating. There are also acrylic paints that are based on organic sovents.  https://https://en.wikipedia.org/wiki/Acrylic_painthttps://strato-editor.com/.cm4all/widgetres.php/com.cm4all.wdn.Separatingline/images/thumbnail.svg

I have been working with acrylic paints for over 30 years, because the paints only need water as a binder. The colours are lightfast for longer, odourless and less harmful to health than oil paints.

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