Overdyeing Lincoln Green — Weld Yellow over Indigo Blue

Prepare a reduced indigo vat following the indigo extraction blueprint — the vat liquid should be yellow-green beneath the surface

Soak the undyed wool skein in warm water for 30 minutes to ensure even dye uptake

Lower the wetted wool gently into the indigo vat — do not agitate, as oxygen breaks the reduction

Keep the wool submerged for 20 minutes, pressing it down gently to avoid air pockets

Lift the wool out — it will be yellow-green at first, then turn blue as it oxidises in the air over 15 minutes

Dip and oxidise 2-3 more times to build a medium blue — not too dark, or the final green will be very deep

Rinse the indigo-dyed wool thoroughly in cool water until the rinse runs clear

Hang the blue-dyed wool to dry completely before the second dye bath — this sets the indigo

Prepare a weld dye bath following the weld yellow dye blueprint — chop 200 g of weld and simmer at 80°C for 45 minutes

Strain out all plant matter and return the golden dye liquid to the pot

Dissolve 10 g alum in hot water and add to the weld bath — this fixes the yellow layer permanently

Soak the dried blue wool in warm water for 15 minutes before entering the weld bath

Lower the blue-dyed wool into the yellow weld bath — the colour will begin shifting toward green immediately

Heat the bath to 80°C and hold for 45 minutes to 1 hour, turning the wool every 10 minutes

Lift a section to check — the blue and yellow combine in the fibre to produce a rich green

For a bluer green, shorten the weld bath time; for a yellower green, extend it or increase the weld concentration

Remove the green wool and rinse in progressively cooler water until the water runs clear

Hang the Lincoln Green wool in shade to dry — the overdyed colour is extremely lightfast and permanent