I found some ink samples for De Atramentis Document inks in my drawer recently. These coloured inks are supposed to be waterproof when dry.

They come in 18 colours including black. The ones that I have are cyan, magenta, yellow and black aka CMYK, the colours used by printers. Since these are the so called true primary colours, I wanted to see if they can be used for colour mixing just like watercolour.

By the way, De Atramentis also has another waterproof black ink called the Archive Ink. In the Document series of ink, there's also a black.

Using liquid coloured inks for colour mixing is more challenging than I expected.

You will definitely need to use an eye dropper. It's best to have an eye dropper for each colour you plan to use.

When mixing, it's best to have a mixing well, and put small amount of inks there for mixing, only adding when necessary. Unlike watercolour tubes or pans, once the ink is contaminated with other colours, it will be impossible to make the colour clean again.

The ink dries rather quickly, which makes it suitable for layering techniques. You can still use wet on wet techniques provided you wet the paper sufficiently.

Once the ink is out on the palette and is unused at the end of the painting session, it's going to be wasted. Unlike tube paint or pans, the ink will dry up. I can't tell if a bottle of ink will last longer than a tube of 15ml colour. But if you're going to use these inks as liquid watercolour, just get the cheaper Dr Ph Martin's Hydrus watercolor which will give you 30ml for around US $8. A bottle of De Atramentis Document Ink can be more than two times the amount. The main difference would be the ink is safe for use in fountain pens.

I still prefer painting with watercolour rather than inks. Watercolour is way more convenient and portable since they can come in tube and pan format. To bring ink around, you will need to bring the bottles or have the inks in small capsules, or tubes. And you'll have to bring eye droppers because pouring the exact amount of ink out from the tube is not easy.

The overall experience of painting with ink vs watercolour is different. As mentioned, using watercolour is more convenient. It's also less likely to contaminate the paint. Even if you squeeze tube paint and other paint come into contact, it's not like inks where everything will start blending together.

Overall, these coloured De Atramentis Document inks are definitely very high quality and concentrated inks. They can definitely be considered liquid watercolour.

Availability

You can find De Atramentis Document Inks on Amazon. Direct affiliate links are below:
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