Charging a wash: why the tilt window is fifteen seconds long
Charging means adding wet paint into wet paint so the two merge without a seam. On a flat wash the usable window for charging is not the whole drying time — it is the first fifteen to twenty seconds after the previous band lands. Miss it and you are glazing, not charging.
Sap green — Warm, olive-leaning foliage green.
| Pigment | Parts | Hex |
|---|---|---|
| Sap Green | 3 : 5 (60%) | #6E8F3C |
| Winsor Yellow Deep | 1 : 5 (20%) | #D9A02B |
| Perylene Maroon | 1 : 5 (20%) | #7B3A38 |
- Load a 20 mm flat with sap green thinned to milk consistency; wipe the ferrule once on the palette rim.
- Lay the first band and immediately tilt the board 10 degrees away from your body using a wedge under the top edge.
- Watch where the bead travels. On 185 gsm it moves about 1 cm per second for the first fifteen seconds, then slows sharply.
- Charge the second band while the first is still glossy — this is the entire technique, and there is no second chance.
- Level the board the moment the last band is laid; do not wait, or the lower edge will carry a dark accumulation line.
- Mop the bottom bead with a dry, thirsty brush if it is wider than 3 mm when you level.
- Expect 185 gsm to cockle. It will flatten under weight once bone dry, but the surface texture will be permanently altered.
The bead is the clock
You do not need a timer; you need to watch the bead. While the bead is moving, the surface below it is still saturated and a new band of equal wetness will marry into it invisibly. When the bead stops moving, the sizing has begun to close and the next band will leave a visible start mark.
On 185 gsm cold press at 21 C the bead travels roughly 1 cm per second for the first fifteen seconds, then decelerates to a crawl. That deceleration is your signal to have the next load ready.
Tilt before you paint, not after
Most painters lay the band and then tilt. By then the pigment has already begun to settle evenly and tilting only drags a wave of water across the surface, producing a tide line. Set the wedge under the board before the first stroke so gravity is working from the very first second.
Ten degrees is enough. Fifteen will make the wash migrate fast enough that you cannot keep up, and you will end up chasing the bead instead of charging it.
What the maroon is for
Sap green with a touch of Winsor yellow deep is a warm, slightly olive green that reads as summer foliage. One part perylene maroon per five parts green, added only at the lower edge, produces a shadow tone that looks like light passing through leaves rather than a painted shadow.
Perylene maroon is a staining pigment. Once it is on the paper it will not lift, so add it last and add it sparingly — a quarter brush-tip is usually enough for a 20 x 28 cm panel.
What matters
- Charge while the bead is still moving — about a fifteen-second window on 185 gsm.
- Set the tilt before the first stroke, not after; late tilting produces a tide line.
- Ten degrees of tilt is the working maximum for a controllable bead.
- Perylene maroon stains and will not lift: add it last and by the quarter brush-tip.
Handling note — Technique notes only. Follow the manufacturer's safety data sheet for pigment handling; staining pigments should not be allowed to dry on skin.