Gouache and watercolor sit on the same shelf in the art supply store and use the same brushes and paper. They’re both water-soluble, both come in tubes, and both clean up with water. So what’s actually different?
Quite a lot, it turns out. I work in both mediums, and they produce fundamentally different paintings — different in appearance, different in process, and different in the feeling they create when you hang them on a wall. Here’s how they compare.
The Core Difference: Transparency vs. Opacity
Watercolor is transparent. When you apply watercolor paint to paper, the pigment sinks into the fibers and the white of the paper shows through. This is what gives watercolor its characteristic luminosity — that inner glow, that sense of light radiating from within the painting.
Gouache is opaque. Like watercolor, gouache uses water-soluble binder (typically gum arabic), but it also contains an opaque white filler — usually chalk or another white pigment — that prevents light from passing through to the paper. Instead of glowing, gouache absorbs light, producing colors that are rich, flat, and matte.
This single difference cascades into everything else.
How They Look
A finished watercolor painting has a quality of airiness and luminosity. Colors appear to float on the paper. Lighter areas glow because they’re literally the paper shining through transparent pigment. The overall feeling tends to be ethereal, atmospheric, and delicate — even when the colors are vivid.
A finished gouache painting has a quality of density and warmth. Colors appear solid and saturated. The matte surface absorbs light in a way that feels velvety and tactile. The overall feeling is more grounded, more physical, and more graphic than watercolor.
Neither is better. They’re different instruments that play different music.
How They’re Painted
Watercolor works light to dark. You preserve your lightest values by leaving white paper exposed, and you build darker values through successive transparent layers. Once color is on the paper, it’s very difficult to cover or remove. This means watercolor demands planning, decisiveness, and a tolerance for irreversibility.
Gouache works in any direction. Because it’s opaque, you can paint light colors over dark colors, cover mistakes, and rework areas of the painting freely. You can start with dark values and build toward light — or work light to dark like watercolor — or alternate freely. This makes gouache more forgiving than watercolor, though it has its own challenges (layering too thickly can cause cracking; rewetting dried gouache can lift underlying layers).
When I Choose Watercolor
I reach for watercolor when I want luminosity, atmosphere, and the sense of light breathing through the painting. Landscapes are almost always watercolor for me — the medium’s natural ability to render sky, water, fog, and atmospheric distance is unmatched. I also use watercolor for subjects where I want a sense of spontaneity and flow — the loose, wet-on-wet effects that watercolor produces naturally are part of the painting’s character.
When I Choose Gouache
I reach for gouache when I want density, warmth, and a matte finish. Florals are one of my favorite gouache subjects — the opaque quality of the medium renders the thick, layered texture of flower petals beautifully. Gouache is also wonderful for food and still life, where I want colors that feel solid and saturated rather than ethereal. And I often combine gouache with watercolor in the same painting, using transparent watercolor for backgrounds and atmospheric areas and opaque gouache for detailed foreground elements.
For Collectors: What to Know
Both mediums are created on paper using water-soluble paint, which means they have the same care requirements — frame behind UV-protective glass, display away from direct sunlight and humidity. Both are archival when professional-grade materials are used.
The visual difference on your wall is significant. Watercolors tend to feel lighter and more atmospheric. Gouache paintings tend to feel warmer and more present. If you’re choosing between the two, the deciding factor should be which aesthetic speaks to you more — there’s no quality or durability difference.
Browse my watercolor paintings →
