You can dye your own upholstery fabric to give your home furnishings a unique color palette for a reasonable price. This project will also enable you to match existing fabric colors with custom dye blends if you can't find fabric in the color you need.
Step 1 - Determine the Fabric Type
Different dyes work with different fabrics. Bamboo, cotton, and other natural fibers can be dyed with fiber reactive dyes, where acid mixes and setters are necessary for most synthetic blends. The easiest way to dye your own fabric is to choose fabrics that are at least 90% natural. Small quantities of synthetic materials won't prevent you from using fiber reactive dyes, but they will soften the colors—they can also increase bleeding if the fabric isn't properly set and rinsed.
Step 2 - Pre-treat the Fabric
The best way to prepare fabric for fiber-reactive dying is to soak it in soda ash (often sold as "washing soda") and water. This breaks down and softens the outer fibers just enough to allow the dye to really adhere. Place the fabric in soda ash and water, and leave it to sit for several hours. While you're waiting, it's a good time to mix dyes. Create the colors you want by mixing the dyes with water per the manufacturer's specifications.
Try taking a small amount of your dye-batch and putting it in a restaurant-style ketchup and mustard squirt bottle. Test a bit of the dye on the edge of a white rag or other unwanted white fabric. Watch the color spread, and look a few millimeters inwards of the edges to determine what the final color effect would be. If you like it, great—if not, adjust the balance of your color. A color wheel is of great help in this exercise, as it can help you know which colors will pull your dye into balance to achieve the look you want.
Step 3 - Dye the Fabric
Make sure there are no lumps in your dye mix, and that the dye water is as warm as possible. Place the fabric in your dye tub. Allow it to sit for three to four hours if it's hot, or twelve to eighteen hours if it's only warm, stirring occasionally. If it is a nice day outside, letting your fabric sit in its dye tub outside in the sun will speed up the process and help the colors to set firmly.
Step 4 - Rinse
Rinse the dyed fabric thoroughly. If you choose, you can do this in the washing machine, but a pre-rinse is recommended in a basement sink or other utility area to avoid residual dye in the washer's basin. Rinse the fabric until the water runs clear, then put it in the washer on a long cycle with warm water and a dye-setting detergent. Remove and dry according to the material type. The dyed fabric is now ready for your upholstery project.