A €3 brush against a €52 brush, same sheet of paper
The honest answer to "do I need an expensive brush" is that a €3 synthetic will produce about 70% of a €52 squirrel brush's drawing. The other 30% is specific, measurable, and it decides exactly which subjects you can paint.
Place card — Daan Park, Taipei
| Kind | Field kit |
|---|---|
| Coordinates | 25.0330, 121.5654 |
| Country | Taiwan |
| Medium | Watercolour |
| minutes on site | 35 min |
| Tools in the bag | Escoda Prado No.4 · Isabey 6224 No.6 · a €3 synthetic No.6 · a €2 goat-hair mop · 12-pan travel palette |
| First published | 2 Oct 2026 |
The four brushes, and what they cost
| Brush | Hair | Size | Price | Weight |
|---|---|---|---|---|
| Escoda Prado No.4 | Synthetic squirrel | 4 | €11 | 6 g |
| Isabey 6224 No.6 | Grey squirrel | 6 | €52 | 9 g |
| Generic synthetic No.6 | PBT synthetic | 6 | €3 | 5 g |
| Goat-hair mop, 12 mm | Goat | — | €2 | 7 g |
The Prado is the recommendation for most people. It is not the cheapest and it is nowhere near the most expensive, and its synthetic squirrel mix holds about 85% of the water the Isabey does at a fifth of the price.
The soak test, which is the only measurement that matters
I loaded each brush fully and dragged a single continuous line across a 250 gsm sheet until it ran dry. This measures water capacity and how the brush gives it up, and it produces a number you can actually use.
| Brush | Line length on one load | Behaviour at the end |
|---|---|---|
| Isabey 6224 No.6 | 62 cm | Stays pointed, releases evenly, the last 5 cm is a fine line |
| Escoda Prado No.4 | 53 cm | Slight flare at 40 cm, recovers if you re-point it |
| Generic synthetic No.6 | 28 cm | Dumps its water in the first 10 cm, then runs dry fast |
| Goat mop | 71 cm | Releases everything at once; unusable for a controlled edge |
The generic synthetic's problem is not capacity, it is *release*. It is built to be cheap and springy, and a springy brush holds water in the belly and then lets it go in one go. That single characteristic is what makes a cheap brush feel like it is fighting you: you load, you touch the paper, and 60% of your water arrives in the first centimetre.
What the expensive brush does that the cheap one cannot
Three things, and they are all about the edge rather than the wash.
A point that survives a wash. The Isabey's tip comes back to a needle after being dragged flat across 60 cm of wet paper. That is what lets you paint a wall with a fat body of the brush and then pull a crisp 1 mm line at the doorway with the same load, without reloading and without switching brushes. On a doorway or a window frame, that saves a minute and, more importantly, saves the tonal match between the wall and the line.
A soft enough tip to lift. Lifting pigment back off damp paper needs a brush that can touch the surface without cutting it. The synthetic is too springy: it digs in and leaves a pale streak with a hard edge. The squirrel tip lifts a soft, controllable amount, which is what the wake and the sky-gap corrections in this log all depend on.
A belly that does not dump. The goat mop is the extreme example in the wrong direction — 71 cm of line, all of it in the first 15 cm of travel. A brush whose release is unpredictable makes every wash a gamble, and gambles do not accumulate into skill.
Where the cheap brush is the right answer
Two situations, and they are not rare ones.
Dry-brush texture. A worn synthetic with splayed hairs is *better* at dry-brush than a good brush, because the splay produces the broken, grainy mark you are after. Cutting the tip off a €3 synthetic to make a flat scrubber is a standard trick for tree bark, stone texture and the worn threshold in the Marrakech doorway drawing.
Plein-air risk. The most common way to lose a €52 brush is to leave it in a public toilet, drop it in a harbour, or have it roll off a quay wall. A €3 brush in the outdoor slot means you can lose the whole kit and replace it for the price of lunch, and the marks it makes in the field are not 17 times worse. They are maybe 40% worse, which on a fast outdoor sketch is often not the limiting factor.
The rule I have settled on: one good brush for the edge, one cheap brush for texture and risk, and the expensive brush only travels when the subject needs a lifted highlight or a long wet-in-wet run — a doorway, a ferry window, a wet street at night.
On prices: Taipei art-shop prices in New Taiwan dollars converted at the time of writing. Isabey in particular varies widely; the same brush was €38 in Lisbon and €52 here.