Staining Science: Making the Boldest, Brightest Tie-Dye!

• Three different types of white fabric samples: linen, cotton-polyester blend, and 100% polyester.  Purchase enough to make at least one 10 inch by 10 inch square of each type.  
• Ruler
• Scissors
• Permanent marker
• Newspaper or rags
• Measuring cup.  It should not be used for cooking afterward.
• Laundry detergent
• Safety goggles
• Rubber gloves
• Clean glass jar, at least 10 oz.  It should not be used for food or beverage afterward.
• Measuring teaspoon and tablespoon.  They should not be used for cooking afterward.
• Fiber-reactive dye powder, such as Tulip Permanent Fabric Dye or Procion Pro MX Reactive Dye, often available at a craft and/or fabric store.  Use a bold color, like red, blue, or green. 
• Salt
• Water
• Sealable plastic bag, 1 gallon size
• Timer or clock
• Soda ash or Arm & Hammer Super Washing Soda
• Plastic container that can hold 4 cups comfortably.  It should not be used for food or beverage afterward.

1. Cut at least one 10 inch by 10 inch square out of the each fabric sample (linen, cotton-polyester, and 100% polyester).
2. Use the permanent marker to label each square with its fabric type.  Because the permanent marker may leak through some types of fabric, if you are not working on a surface that can be stained, you should label the fabrics on top of newspaper or rags.
3. Pre-wash the fabric squares by putting them in a normal clothes washing machine with ¼ cup laundry detergent.  Wash using hot water, if possible.  Allow the fabric squares to air dry.
4. Before opening the dye powder packet, cover the area you will be working on with newspaper or rags so that you will not stain it.  You may want to work outside to avoid staining something.  Also put on clothes that you would not mind staining.
5. Dyes often contain soda ash (sodium carbonate), which is caustic.  Wear goggles and gloves when mixing the dye solution, mixing the soda ash solution, and rinsing the fabric samples after dyeing.

1. Put on gloves and safety goggles.
2. Put 2 teaspoons of powdered dye, 1 tablespoon of salt, and 1 cup of warm water into the glass jar.  Mix thoroughly.  How does the dye look?
3. Wet the fabric squares and place them in the sealable plastic bag.  Carefully pour the dye solution into the bag and add ½ cup of water to the bag.  Seal the bag, trapping as little air as possible.  How does the fabric change when the dye is added?
4. Let the bag sit for 20 minutes.  Every couple of minutes, gently squeeze the bag to coat all of the fabric samples.  
5. While the fabric’s soaking, mix 1 tablespoon of soda ash (or Arm & Hammer Super Washing Soda) with 2 cups of warm water in the plastic container.  Break up any hard pieces that form.
6. After the fabric’s done soaking, carefully open the plastic bag and add ½ cup of the soda ash solution.  Reseal the bag, trapping as little air as possible.
7. Gently squeeze the bag to mix the soda ash, dye, and fabric.  Let the bag sit for 1 hour, gently squeezing every 10 minutes.
8. Carefully dump the contents of the bag into a sink and rinse the fabric until the water runs clear.  
9. Wash the fabric samples in the washing machine just as you did before.  Allow the samples to air dry.  When you are done handling and disposing of the soda ash solution, you can remove your goggles and gloves.
10. Once they’re dry, how do the fabric samples look?  Did some types of fabric become dyed to a darker shade than others?  Did some types not absorb much dye at all?   

Extra: In this activity, you tested how well linen, cotton-polyester, and polyester samples were dyed using a fiber-reactive dye.  But there are many other types of fabric you could test dyeing, such as cotton, wool, rayon, silk, and nylon, and they may react differently.  How well do other types of fabric become dyed with a fiber-reactive dye?

Extra: Before synthetic dyes were created, humans used natural dyes.  Do some background research and pick one or more natural dyes to try in this activity.  You will probably want to use relatively safe dyes, like turmeric or berries.  Do some natural dyes work better than others?  Does it depend on the type of fabric used?

Extra: Some dyeing methods suggest pre-soaking the fabric in soda ash solution, and then adding dye (the reverse of what is done in this activity).  Does the order of these steps make a difference in the color of the dyed fabric?