Due to the somewhat complex weaving process used to create it, and its soft sheen and vibrancy, velvet has long been considered a luxury fabric. Velvet has traditionally been woven using silk fibres. Natural fibres like silk (and thus velvet) can be dyed easily, often with rich colour results. However, with the common modern practice of blending natural fibres with synthetics, it is critical to check the fibre content of your velvet fabric to determine the best dyeing method. Additionally, note that it is nearly impossible to dye polyester so if your velvet contains this material it cannot be dyed.
Wash your velvet fabric to remove dirt and grease. Don't dry the fabric, as it needs to be wet for dyeing.
Fill the stock pot with hot water and put it on the stove on medium-high heat. Ensure that there is enough water and room for the fabric to move around freely during the dyeing process.
Dissolve the acid dye powder in 1 cup of hot water, then add to the dye pot. Follow the manufacturer's guidelines for the amount of dye to use.
Add the wet velvet fabric to the pot. Stir the fabric for a few minutes to evenly distribute the dye.
Bring the temperature of the water to 85 degrees Celsius.
Pour your white vinegar or citric acid into the dye pot. Use 1/4 cup of vinegar or 1 tablespoon of citric acid per pound of fabric.
Stir the dye pot frequently and maintain the temperature for 30 minutes to an hour, depending on how deep you want the colours.
Remove the velvet from the pot and rinse with warm water. Wash in a regular wash cycle with a cool water rinse.