Fabric Medium is an acrylic polymer liquid blend, that has no pigments, which you can mix with your acrylic paints to give your painted fabric a beautiful soft feel.
To prevent your fabric from adhering to your work surface, you need to lay down a protective sheet. Insert a piece of cardboard inside a t-shirt to obtain the best results.
Some types of fabric that are suitable for painting are flannel, cotton-poly blends, suede, knitted, leather, cotton, corduroy, woven, most synthetics and silk.