It doesn't seem like a lot of people know the difference between watercolor and
gouache so I wanted to make a video that shows how watercolor works versus how
gouache works. So, first of all, watercolor is a transparent paint and it is diluted
with water and it's binder is gum arabic, which is a rather weak binder. As a
result, watercolor doesn't have a natural sealer in it like acrylic or oil. When
they dry, the're waterproof, and watercolor obviously is not. So you can see it's
transparent and luminous and very lovely. Gouache is also a water soluble paint so
the first comparison is that watercolor is transparent and luminous
and gouache because of the zinc oxide or titanium dioxide is opaque and duller
and more matte looking, more of a velvety finish. So you can see that I'm using
sort of the same thickness of gouache on the right side there and it is not
luminous and transparent looking like the watercolor on the left. It's just a
bit more sort of chalky looking, and a bit more dull if you want to go really
dark with a watercolor or with gouache the trick is just of course layer so you
can layer watercolour and you have to wait till watercolor
layers are dry before you go to the next layer, unless you want the colors to mix.
With gouache the drying time is actually pretty instant so the big thing
with watercolor is is you really have to love the luminosity of it and the
diverse effects you can get with it. When it comes to the different mediums,
watercolor really is the most luminous and beautiful and nothing else can
really capture that sort of light quality of transparent colors of
watercolor. You can drop water back into a painted area and you'll get these
blooms. You can get all these great watercolor textures and
water effects from how the water dries around the paint and in the paints and
how the colors mingle together, and you can add other things to it to increase
the effects like salt or sand, and sponging, all sorts of things.
With gouache, it actually is more limiting than that you because if you
thinned it down to the point of it being transparent then why aren't you just
using watercolors? So, if you're going to be using gouache the way gouache is
meant to be used, which is a little bit thicker, gouache has that opacity in
it because of the pigment type or titanium dioxide, and so it will not budge as much.
You can still do sort of blurred effects and impressionist effects by doing loose
brushstrokes but it's very much like acrylic and oil in that sense. You
can do an impressionist painting or you can do a more realistic painting, but you
can't really do water effects or textures the way that you do with
watercolor. When it comes to white for watercolor and gouache, both mediums
treat it differently. So, for example if I wanted to have a circular brown shape
here and save the middle as white I need to make sure I save the white of the
paper if it's a watercolor. If I was to dip into some white paint then what's
going to happen is my watercolor is going to turn into gouache, so if I want
to maintain the transparent luminosity of watercolor I need to make sure I save
the white of the paper and paint around any white highlights. I can also lift out
certain amounts of paint on other parts of my paper so if I have a highlight
that I want to lift out because I forgot to save it or because I prefer a blurred
edge. Sometimes it gives you a nice softer blurred edge if you lift out
rather than saving the white. Then you just have to lift out with a brush, just
a damp brush with water and then dab out with a paper towel or a chamois or a
washcloth and you'll end up saving some of that white and it will come back. But
I can't use white paint so watercolor has no white paint. For
gouache you do have the white paint. Gouache is constantly using the white
paint, it's what's giving it body and tints, so if you want a pure white area you don't
have to save it. You can just go back on to any part of your gouache painting and
add white or you can save the white of your painting and then come back on
there with with more white with gouache. It doesn't matter, you can add light, you
can add dark, and both will work just fine. So you don't really see much of your
paper when you're painting in gouache, whereas with watercolor you see a lot of
the paper and when you're seeing white you're actually seeing the white of the
paper. There's also a difference in the two
mediums when it comes to glazing. So with water color you can add glazes as long
as your under layer is completely dry you can add a top color glaze in any
color and it will make the entire color tone shift towards whatever you want. In
this case, this dark blue green. And we cannot do that with gouache even though
you can do this with acrylic and oil because they dry completely between
layers. The paint in watercolor sort of sinks into the paper, with gouache it's
more sitting on top of the paper, so when you go to add a glaze to gouache it just
smears that entire white. Gouache paint is thicker in general than watercolor
and as a result of that you really can't add a glaze over the top of it because
the water will make the entire shape smear. So you can't really do that with
gouache, but you can do that with watercolor. I'm also going to show you a
quick example of how gouache and watercolor lift off: So you can see
there's some very ugly leafy sort of shapes, I really don't know what they are
actually, but keep in mind that the ugly leaf shape is in ink so it's not going
to lift off. What I'm trying to show is the rest of the colors on top lifting
off so you can see that watercolor does lift off very well and the gouache also
lifts off very well. The only other thing I should point out is that if you're
trying to cover up a mistake. Say I wanted to cover up that
ugly ink leaf--with watercolor, it would be almost impossible. If I wanted to cover
up that ugly ink leaf on the gouache side, however, I could just use the opaque
wash paint to cover it up and I could hide it pretty well. I'm just going to
also now do a quick sphere in watercolor and gouache. You can spend a lot more time
on this and do far more layers and depending on what you're going for.
You can see how I've applied the different principles of watercolor and
of gouache for the different spheres, and how I've saved white for the watercolor
sphere, and how I have just painted white on top for the gouache sphere, and also
how I've waited for layers to dry in between for the water color, and how I
don't really have to do that for the gouache, and you can again keep making a
comparison between the watercolor and gouache and how they look. I've done
videos that show
in-depth projects that are a watercolor versus gouache project, so I hope this is
helpful to you and that you enjoy those other comparative videos as well!