You can find great deals on eBay for grey clothing dye.
You need to use black dye in a certain way to get gray, so it may be difficult to dye a shirt gray.A plain white cotton T-shirt can be dyed to a shade of gray.Depending on what shade you want, you need to use less black dye.If you want to dye your fabric in the right shade of gray, follow a few steps.
Use a small amount.There is black dye powder for each pound of fabric.For a medium shade, 6 cups.For a dark shade.For dark color.Dissolve the dye in two cups of room temperature water per pound of fabric.
Add 2 1/2 gallons of room temperature water per pound and 1 pound to the dye bath in the bucket.1 1/2 lbs. of salt for light gray.Medium and 2 lbs. of salt.For darkness.Stir some more when you add the dissolved dye.