I only know of two brands that make watercolour sticks, Daniel Smith and Winsor & Newton. The four colours I bought are Hansa Yellow Medium, Permanent Alizarin Crimson, French Ultramarine and Cobalt Blue.
I've already reviewed the WN watercolour sticks and was quite disappointed by their quality. The Daniel Smith watercolour sticks are way better in quality than the Winsor & Newton's, although it's not without its quirks.
The DS watercolour sticks are much larger then WN's.
The diameter is thicker than a wooden pencil.
The difference between watercolour sticks and the other water-soluble sticks or crayon is you get more information regarding the pigment used to make the sticks. For example, for Derwent Inktense blocks or Caran d'ache Neocolor II, there may be lightfast information, but there's no information on pigment used. Some manufacturers also like to use fancy names for their colours, such as Derwent giving colours names such as Fern, Baked Earth, Dark Chocolate, Peacock Blue, Dusky Purple, etc.
In the case of DS and WN watercolour sticks, they use the same pigment that are used to create the tube paint. DS says each stick is packed with pure pigment. That I do not doubt because when you wet the sticks, the colours they produce are extremely vibrant, no different from the tube paints. And they are easy to dissolve.
There's no mention of the binder used though so I'm not sure what's holding the pigment together. The downside of the DS watercolour sticks is they are too soft compared to the WN ones.
When I tried using them like normal crayons, the tips would become misshapen quickly, as if I'm using a kneaded eraser. This softness affects Hansa Yellow Medium and Permanent Alizarin Crimson.
The yellow is so soft, I can press it into some other shape.
The two blues I have are harder but no less difficult to use for drawing. When rubbed across paper, they produce flakes, just like how you would produce flakes from rubbing plastic erasers.
I thought the problem was cause by the humid weather here in Singapore so I put the four sticks into a dehumidifier box. The next day when I took them out of the box to use, they were still soft. As such, I conclude that using them for drawing like crayons is not the most appropriate way to use them. And they would become softer under the sun.
Here's what you get when you apply the sticks on coldpress paper. They are too soft to get into the valley of the tooth of the paper texture.
They dissolve rather easily and completely which is an attribute that I really like. Usually for water-soluble pencils or crayons, they often leave behind undissolved bits. Not so with the DS watercolour sticks.
Those flakes can also be dissolved, of course.
The other way to use the sticks is to use a wet brush and get the pigment onto the brush directly. Because the pigment dissolves so easily, you can create an intense wash very easily and quickly.
Dissolving the sticks with the brush allows you to create flat washes, just like you would when you dissolve pan or tube colours.
If you want to put more pigment on the paper, you can just rub them off with a wet brush from the stick straight to the paper.
Another handy way to use the sticks is to use them to create splatter. Just wet the stick with a brush and proceed to splatter. It's easy and it's not messy to handle.
Currently, I'm storing the sticks in a tin box together with the WN sticks. When it's wet, it can make a mess with everything in the box.
Daniel Smith actually sells plastic compartment cases to hold the sticks. It's definitely more convenient to transport the sticks this way, not to mention it's much cleaner. Each case can hold 5 sticks. The cheapest place to buy them seems to be from Daniel Smith's website and they cost USD $3.50 each.
The Daniel Smith watercolour sticks are really high quality. When wet, the colours they can create are intense. Quality is no different from the Daniel Smith tubes.
I think these watercolour sticks represent tremendous value for money. Each stick probably comparable to 10ml worth of tube paint. Because the sticks are soft, you can actually cut them and put them into the plastic half pans. One stick can fill 5 half pans. The advantage of doing this is, you don't have to wait for paint to dry in the pan. The downside is, they are more difficult to refill partially.
Being able to use the sticks to create splatter marks without making your hands dirty is so convenient.