Ground inner bark of Quercus velutina, sometimes known as Quercitron.
Use on protein or cellulose fibres. A well-respected source of strong yellows. Pre-mordanting recommended. Alum/c.o.t. mordant gives excellent results. Use at 10-20% WOF for medium shades.
TO USE: simmer in water at 160-175°F for 1 hour. Cool overnight and strain. Add more water if necessary and enter pre-mordanted fibre. Hold at a 160-175°F for one hour. The brightest yellows develop at these cool temperatures.
Light and washfastness: excellent with a mordant.