From the manufacturer:
Colors print on a range of fabrics with bold, opaque color, they dry to the touch overnight, and remain permanent through the wash-with NO HEAT SET REQUIRED!
Love creating unique designs on fabric but hate heat-setting? Then Speedball’s Fabric Block Printing Inks are for you! Made from a water-washable oil, these inks print with bold, opaque color and maintain a soft hand. All colors carry the AP Seal and clean up easily with soap and water. Get ready to breathe new life into your designs with these vibrant hues that will leave your creations blooming with beauty.