Dyeing of fabric has been done for centuries, the colorants coming from different plants, insects, and even snail mucous. It was not until 1856 that the first synthetic dye was discovered by a chemistry assistant and student named William H. Perkins, when he was trying to make a synthetic form of quinine. Quinine is a plant-derived substance that used to be used to treat malaria.
Synthetic dyes have become widely used, because the focus on the chemistry of the dyes makes it easier to reproduce them. Alternately, some of the natural dyes and their processes have only been reproduced by word of mouth. Discovering the right way to make a natural dye work, so that it is bright enough, consistent, and color fast is knowledge sometimes lost to us. In the first video you will see how Sachio Yoshioka follows the clues in order to re-discover some natural dyes.
Sometimes used in talk about dyeing is the word mordant. A mordant is a substance that aids in keeping colorants in the fabric. Also, different fabrics sometimes come out as different colors with the same dye. Perhaps a reason for this is that some fabrics are made of cellulose fibers, like cotton, hemp, and linen. Also, some fabrics are made with protein fibers, like suede, leather, wool, and silk. Protein fibers tend to take dye better than cellulose fibers.
If you would like to know more about the basics of the different building blocks of dyes, the following web site tells something about how different types of dyes work by Sara J. Kadolph: https://fashion-history.lovetoknow.com/fashion-clothing-industry/dyeing
The next video is a little over an hour and is where an Australian woman tells about some of the dyes she has made with basic plant ingredients, along with an interesting demonstration of using rusty objects, water, lemons, and salt to make a pattern on an old wool blanket. She also makes some prints by taking some plants she sets on different types of fabric, ties them up, while she steams some, she also boils some with eucalyptus leaves, which is a mordant.