Dyeing Yellow-Green with Persian Berries — The Buckthorn Dye of Ancient Manuscript Painters

Use 50-100% WOF of dried Persian berries. For 100 g of wool, weigh out 50-100 g of dried berries. The berries should be small, hard, and dark greenish-brown to black when dried. They are sold by specialty dye suppliers. Crush the berries lightly with a mortar and pestle to break them open and expose the inner seed and flesh — this dramatically increases the dye extraction rate.

Place the crushed berries in a dye pot with 4 litres of warm water and soak overnight (8-12 hours). The water will turn a greenish-yellow as the flavonoid glycosides dissolve. The overnight soak allows the hard berry shells to soften fully and release their dye content. By morning, the liquid should be a distinct greenish-gold.

Bring the pot to a gentle simmer (75-80°C) and hold for 45 minutes. Stir occasionally. Do not boil — excessive heat shifts the colour toward dull brown. The liquid will deepen to a rich greenish-yellow to golden-green. The crushed berries will release their remaining dye during this simmering period.

Strain the dye liquor through a fine mesh strainer into a clean pot. Berry fragments and seed particles can stick to wool and cause uneven spots — strain thoroughly, pressing the pulp to extract all remaining liquid. For the cleanest results, strain a second time through muslin cloth. The strained liquor should be a clear greenish-gold.

Pre-wet the alum-mordanted wool in lukewarm water for 15 minutes, squeeze gently, and lower it into the Persian berry dye bath at room temperature. Slowly raise to 75-80°C over 15 minutes, then hold for 45 minutes. Turn gently every 10 minutes. The wool will develop a distinctive yellow-green — the characteristic Persian berry colour that manuscript painters called stil de grain. The alum mordant produces the brightest, most vivid version of this colour.

Turn off the heat and let the wool cool in the dye bath overnight. Remove, squeeze gently, and rinse in lukewarm water until the runoff is clear. The final colour is a unique yellow-green with a warm olive undertone — a shade that is difficult to achieve from any other single dye source. Lightfastness is moderate — better than turmeric but not as permanent as weld. The colour will shift slightly toward warmer gold tones with prolonged light exposure. Dry in shade.