Lac Extract – a red dye extract from the scale insect Laccifer lacca and can found throughout India, south east Asia, Nepal and south China. It is harvested from both wild and cultivated means. The female lac insects invade host trees and secretes a resin that contains the red dye. The resin is harvested and taken off the branches and is known as stick lac. The resin contains both shellac and dye. The dye is extracted from the resin and the remaining shellac is further refined into other products. The colors are similar to cochineal but softer and warmer in appearance.
- Dye Amount: 5-8% WOF
- Color: crimsons, burgundy reds and deep purples
- Light fastness: High
- Wash fastness: High
- Alum mordant at 15% WOF for protein fibers
- Alum mordant at 8% WOF for cellulose fibers
- Tannin mordant at 8% WOF and then alum at 15% WOF, or alum acetate at 8% WOF
- Dyeing: Dissolve extract in water and simmer with fiber for 45-60 minutes. For the richest colors, leave the dye pot to soak over night. Lac dye is very sensitive to change in pH and develops to its fullest color potential with the addition of cream of tartar at 6% WOF. For plum purples, add an alkali such as cream of tarter. For blackened purples, add ferrous sulfate.