Here are some unscientific tests between the Aquazol binder that's used in QoR watercolour and gum arabic used by many other brands.

Aquazol (Poly(2-ethyl-w-oxazoline) was first patented in 1977 by Dow® Chemical. It's a watersoluble polymer designed as a substitute to gum arabic.

Aquazol is said to be able to hold more pigment than gum arabic. Based on the swatches above, the colours from QoR, Daniel Smith and Maimeriblu all look very intense.

Aquazol is supposed to be transparent as opposed to gum arabic which has a light yellow tint. Have you ever open a tube of watercolour and the gum arabic has separated and flowed out? Remember that colour? It's light yellow. However when watercolour is diluted, the light yellow doesn't really affect the colours.

Another characteristic of Aquazol is its strength. It's said to be able to resist cracking more so than gum arabic. This and its resoluble behaviour allows conservators to use Aquazol for conserving painting. You can read more about Aquazol in conservation practice here and here.

These are colour mixes created within brand. There's not much visible difference. The colours from Daniel Smith may look like they don't blend as softly but that's just my technique which is off.

These are colour swatches created by mixing with other brands. QoR + DS means the top colour is QoR and the bottom is Daniel Smith.

It seems like Aquazol and gum arabic watercolours have no problem mixing together.

The only part where I see a difference is when working wet on wet.

When you drop QoR watercolour onto a wet surface, a lighter version of the colour will "explode" outwards while the concentrated paint spreads slowly. With other brands, the paint would move but not is such a dramatic manner.

Click for a larger view.

For the picture above, I dropped Quinacridone Magenta (PR122), and while the wash is still wet, I added Nickel Azo Yellow (PY150). The paper was flat and it seems like the blending wasn't as smooth as I expected. When working on angled paper, the blend may be smoother.

I've reviewed QoR watercolor before and the quality is good. As for Aquazol vs gum arabic, for painters or casual sketchers, the difference is not significant. Art conservators may appreciate the Aquazol characteristics more.

Video review

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