I earlier wrote an article about what is gouache. Now I’ll list several of gouache’s strengths.
Keep in mind that from my perspective, you want to use tools for what they’re made for. If a tool has certain strengths but you have another tool that is better at other strengths, you use your tool for its strengths and the other tool for its strengths.
Watercolors and gouache play very nicely together. I use both in the same painting in almost every one of my paintings.
Gouache is opaque
There are times you want transparency. And times you don’t.
For the times you don’t, use gouache.
I use gouache for black hair, white wave splashes, and to cover up watercolor mistakes that I couldn’t get out with water or cover up with normal watercolors.
Since gouache is opaque, you can paint gouache over watercolor and it covers up the watercolor. Obviously, it’s great for the uses I just mentioned. Especially to cover up mistakes that I really, really need covered up.
Gouache is fast
You can paint gouache fast. And gouache dries fast.
Now, if you got all the time in the world, ignore this point.
If however you got deadlines, you’ll want to use gouache for something you have to get done asap.
Big areas of one color?
Want to make a quick cartoon?
Those are just examples but I’m sure you get my point.
Gouache is easy
Well, nothing is easy. But if you want to compare the two mediums, I’d say gouache is easier to learn with.
Your painting will be more WYSIWYG (what you see is what you get).
I personally think it takes a lot longer to learn how to get good at watercolors than how to get good with gouache. I’m pretty sure I’m of the majority opinion here.
Just in case you didn’t read my bio, I started off as a cartoonist. If I ever want to get back into cartooning, I’ll be using more gouache than watercolors. I can get characters done quickly with gouache whereas skin color in watercolors is layer after layer after layer to look good.
And now for a quick disclaimer – I almost never use gouache as my primary so if you want to ask more obscure questions about gouache, I’m the wrong person to ask. I know it just enough to get what I need to get out of it.