Things You'll Need
Instructions
Buy a piece of muslin large enough to cover the area you want hidden in your photos. Muslin, along with black fabric dye is found in any fabric store. Wash the muslin in your washing machine. Do not dry it; move it directly from the washing machine to the dye bucket.
Fill a large bucket with hot water. You want to do this outside so that if you spill dyed water onto the ground, it doesn't stain anything in your home or office. Measure the correct amount of black dye into the hot water -- instructions are specific to the shade and type of dye you are using and are provided with the dye.
Put on a pair of elbow-high rubber gloves and mix the dye with your gloved hands until the water is saturated with the dye. Place the muslin into the water and mix it around until the fabric is completely coated with black dye.
Remove the muslin; if it did not dye the way you wanted it to, you can place it back into the bucket and keep moving it around until it turns the color you want.
Dump the bucket of water out and replace it with cool water. Place the dyed muslin in the cool water and move it directly from the cool water to your washing machine for one more wash. Once the dyed muslin is washed, you need to hang it on a clothesline to air dry.
Hang the dry, dyed muslin on a wall or place it over an existing background object until you have the desired black background you want for your photos.