Can you swap synthetic brushes for natural-hair in gouache work? a practical test and maintenance plan

I’ve been asked more times than I can count: “Can I swap synthetic brushes for natural-hair when working in gouache?” It’s a great question, especially as gouache sits somewhere between transparent watercolor and opaque acrylic in its behaviour. I decided to run a practical test in my studio to answer it properly — not just theoretical pros and cons, but how the brushes actually perform, how they hold and release gouache, and what maintenance they require so you don’t shorten the life of an expensive natural-hair brush.

Why the question matters

Gouache is water-based but often used more opaquely and with heavier pigment load than watercolor. That means brushes are subjected to thicker paint, more frequent rewetting, and sometimes more scrubbing. Synthetic brushes have become popular because they’re cheaper, resilient and easy to clean. Natural-hair brushes — sable, squirrel, kolinsky, goat — are prized for their spring, softness and ability to hold a lot of liquid. But are they practical for gouache, or will they get ruined quickly?

My test: what I tried and why

I selected three common brush types I already use in the studio:

Synthetic round (size 6) — a popular affordable option from Princeton Velvetouch.

Sable-hair round (size 6) — a mid-range Winsor & Newton series.

Goat-hair mop (approx 14mm) — used for washes and soft blending (Da Vinci Maestro imitation).

I worked on Arches cold press paper and a smooth hot-pressed cartridge paper to see how surface texture affected wear. My paint choices were three gouache brands I use regularly: Winsor & Newton Designers’, Schmincke Horadam, and Holbein Artists’ Gouache. I used the same palette of opaque colours and mixed thicker buttery mixes and more diluted washes.

Test criteria:

Paint pickup — how easily the brush took up mixed gouache.

Holding capacity — how much paint/water it could carry.

Release and stroke quality — whether marks were smooth, or splotchy.

Resilience — spring and return of the tip after a few marks.

Ease of cleaning — how much residue remained and how quickly it returned to shape.

What I found

Paint pickup: Natural-hair brushes, especially the sable and goat mop, held more fluid and paint than the synthetic in a single load. The goat mop in particular absorbed a good deal of pigment and returned very soft, velvety washes. Sable gave a lovely, precise pickup for smaller rounds.

Holding capacity: Sable held enough to lay down clean, controlled opaque strokes without frequent reloading. The synthetic needed reloading more often, especially with thicker gouache mixes. For quick, gestural marks, that’s not a problem, but for longer hairlines or larger filled areas it became tiresome.

Release and stroke quality: This is where natural hair shone. Sable produced crisp lines and a responsive tip; the goat mop made gloriously smooth soft blends and was forgiving on surface texture. The synthetic gave nice marks, but the edges were slightly less nuanced — still perfectly acceptable for many illustration and blocking-in tasks.

Resilience: After prolonged work, the sable retained spring better than the synthetic. The synthetic’s bristles tended to splay slightly faster when I used a lot of scrubbing for texture. The goat mop naturally has less spring, which is expected.

Cleaning and maintenance: This is the crucial point. Natural hair took more effort to clean. Gouache dries water-soluble, but once pigment sinks into hair and dries repeatedly, it can be stubborn. On the first session, I could clean the sable back to good shape with warm water, mild soap (I use Masters’ Brush Cleaner) and gentle reshaping. After two sessions of leaving gouache to dry in the hair, however, the sable and goat showed some staining and slight matting, especially with the darker pigments (Prussian blue, Payne’s grey). The synthetic rinsed out quickly and returned to shape with minimal fuss.

Practical maintenance plan (step-by-step)

If you want to use natural-hair brushes with gouache, here’s a routine that kept my sable and goat brushes working well over a few weeks of regular use:

During painting: Keep a jar of clean water and a spare rinse jar. Wipe excess gouache on a rag before rinsing — this reduces pigment build-up inside the ferrule.

Between sessions: Rinse thoroughly in warm water until the water runs clear. Use a soft brush soap (Masters, Zest-it is for solvents; I prefer a gentle glycerine soap) to dissolve pigment; lather gently and reshape the tip with your fingers.

Deep clean weekly (if you paint daily): Use a concentrated cream brush cleaner or a tiny drop of gentle dish soap in warm water to remove surface oils and dried pigment. Work from ferrule to tip rather than scrubbing the tip only — this pushes pigment deeper if you do it the other way round.

Drying: Always dry horizontally or with the tip up to prevent water running into the ferrule and loosening the glue. Don’t leave brushes standing tip-down in jars.

Storage: Store sable and fine rounds vertically with tips up, or lay flat in a brush roll. For long-term storage, insert a short strip of paper between ferrule and handle to protect the glue when humidity fluctuates.

Rescuing splayed tips: If tips flatten, use brush soap and reshape while damp. For stubborn splaying, a dot of warm water mixed with a little glycerine can help rejoin hairs while you reshape and let dry.

Quick reference: pros and cons

Type	Pros	Cons
Synthetic	Inexpensive, durable, easy to clean, good for heavy scrubbing	Less liquid capacity, slightly less spring for fine lines
Sable	Excellent point and spring, holds paint well, great for detail	Expensive, needs careful cleaning to prevent staining and matting
Goat mop	Fantastic for soft washes and blends, excellent absorption	Low spring, heavy maintenance, not ideal for fine lines

Brands and models I recommend

If you’re curious about trying natural hair, these performed well for me:

Winsor & Newton Series 7 (sable) — classic sable with reliable spring and point.

Escoda Reserva (sable) — excellent build quality and resilience.

Da Vinci Maestro mop (goat) — large, fluffy, perfect for soft gouache washes.

Princeton Velvetouch or Silverstone series for synthetic rounds — good synthetic alternatives with a surprisingly natural feel.

Final thoughts (practical guidance)

Yes — you can swap synthetic brushes for natural-hair in gouache, but it depends on your working method and how much maintenance you’re willing to do. If you paint fast, layer often, and don’t want to fuss much, synthetics will give you reliable, low-maintenance results. If you value subtlety of stroke, point, and the ability to hold a lot of paint for controlled marks or feathered washes, natural-hair brushes reward you with superior feel — provided you commit to careful cleaning and storage.

In my practice I often keep both: synthetics for priming, scrubbing and heavy blocking-in; sable for precision, glazing and polished edges; and a goat mop for those soft atmospheric washes that make gouache sing. Having this mix gives flexibility without constantly risking my nicer brushes.