If you've ever tried to buy tulle, you already know it doesn't come in a wide variety of colors, and as such, finding it in a particular color (such as matching it to a wedding's color palette or a costume) can be difficult. Fret not--tulle can be easily dyed depending on the fabric's fiber content. Most tulle is made with nylon, so dying it with acid dyes usually gives you the easiest results and the color you desire. Hand-dyeing at home with your top-loading washing machine is optional for this project.
Pre-wash your fabric with a detergent containing synthrapol if at all possible. This is because the dyes generally occupy the same molecular space as common detergent. A good brand with synthrapol is available at feed stores under the brand name Orvus. It's not entirely necessary to use a synthrapol detergent—an ordinary one will do—but your results will be better if you can use a synthrapol-laced detergent. Either way, pre-washing is important and will determine the overall quality of your efforts.
Weigh your fabric. Dying 5 lbs. at a time is optimal. Since tulle is exceptionally lightweight, 3 lbs. should fill your washing machine.
Place your washing machine's settings on the longest hot wash/cold rinse cycle. Fill the water to where it will just cover your fabric, wet it, and then pull it out and set it aside.
Follow the dye manufacturer's instructions, adding the appropriate amount of dye for the color you would like to achieve. Agitate the dye until it is dissolved.
Add 1 cup of vinegar without pouring it directly onto the fabric and allow to agitate for a few more minutes. Allow the machine to cycle through the complete washing cycle. You can stop the machine and reset it to the beginning of the wash cycle if you want to ensure a better permanence of the dye.
Allow the cycle to complete, and run it through an additional cycle in case you want to remove any excess dye. Then remove fabric from washing machine.
Clean the washing machine by running it through an additional cycle to clear out any dye left in the washtub or the machine's plumbing.
Carefully keep records of how much dye you use so that you can use the same amount again in subsequent loads. If you use different amounts, you will achieve a different color, so be careful.