This is Old Fustic shavings that gives warm yellow. There is 2 pics of same silk cloth, one taken without sunlight under white light which is little darker then the other pic taken with sunlight interference.
Old fustic ( maclura tinctoria or Chlorophora tinctoria ) is a mulberry tree similar to North American Osage Orange ( Maclura pomifera ).
Old fustic is used for producing yellow and Khaki fabric. The coloring matter of Fustic consists of two principles, one much soluble than the other. if allowed to stand separate into two layer, lower consisting of rather insoluble morin and upper macluria. A proper mixture of the two is needed while dyeing. For that reason fustic in powder extract and chips were preferred.
Fustic works best in netural or even slightly alkaline bath but does not do well in acidic bath. It has excellent wash fastness and good light fastness. Alone It gives warm yellow, for green addition of logwood or iron or copper. The best permanent black is obtained from logwood with fustic and iron.
Extracting dye from shaving is done like any other wood dye such as brazilwood, logwood, and sandlewood. Take the required shaving and soak in warm water overnight or a day, the longer you soak, it will extract more dye when boiling it. Soaking in water soften and makes it easy to break the cell walls to extract more dye.
Take the soaked material and add to dye pot. Heat to the boiling point and boil for an hour or more. Remove the shaving and add the fabric to dye.