Tuesday, October 19, 2010

How to Paint Hemp Roving (& Other Cellulose Fibers)

This tutorial shows how to paint hemp roving. You can use this same method for dyeing cotton, bamboo and other cellulose fibers.

Here are the materials I'll be using:
4oz of 100% Hemp Roving
1/2 teaspoon Procion Dye (I like to use Procion Dyes from Dharma Trading, but any brand of fiber reactive dye is acceptable)
1/4 cup soda ash (or your mordant of choice)
5 tablespoons of salt
9 x 13" Clear Pyrex Dish
Microwave Oven
Gloves, Bowl, (4 cup)Measuring Cup, Measuring Spoons (your dyeing dishes and utensils should be separate from the ones used for food)

Let's get started.
Begin by pre-soaking your fiber for at least 30 minutes. If you are concerned about your fiber being thoroughly clean, you can add just a few drops of mild soap to the water. After 30 minutes have passed, It's time to prepare a mordant bath to scour and prepare the fiber for dyeing. In a bowl, mix 1/4 cup soda ash with the hottest tap water. Stir until the soda ash has completely dissolved in the water. Take your hemp from the pre-soak and squeeze out all the water. Then transfer the hemp into the mordant bath you have just created. Let the hemp sour in the soda ash for 5 minutes.

The picture on the left shows the hemp in the pre-soak. On the right, the hemp has been transferred to the mordant bath. You can see that the water is a little cloudy from the soda ash.

While your hemp is scouring, you can prepare your dye bath. Using a 4 cup measure. mix 4 cups of warm tap water with 5 tablespoons of salt and 1/2 tsp of your dye powder (or the amount indicated on your brand of dye). Stir until the salt is dissolved and the color is completely mixed.

After five minutes, wearing your gloves, remove the hemp from the mordant bath squeezing out all excess water. Lay the hemp out in an even layer in the Pyrex dish. I like to go back and forth in a zig zag motion.

Now it's time to paint. Keep those gloves on because we are going to be finger painting. Give your dye bath one more stir to make sure it's completely mixed, then carefully pour the dye water over your roving.

Use your hands to work the dye into the fiber. The reason I use my hands and not a brush to paint is because roving likes to cling together when it's wet. The most challenging part of this process is making sure that the dye reaches the core of the fiber. In the picture on the right, I am gently teasing the roving apart to see if my dye has worked all the way through.

Take your time with this part of the process. I like to carefully gather the roving and turn it over in the dish at least once so I can work on both sides. It's also nice to have a clear dish because you pick it up and look through the bottom of the dish to see if the dye has gone all the way through or if there are bare patches in your fiber.

When you feel confident that the hemp roving is evenly painted, cover your dish with plastic wrap. Use a knife to create a few vents to allow steam to come out. You can see that my plastic is a little cloudy. That's because our dye bath was warm, but now it's time to turn up the heat.

Place your dish in the microwave. My microwave is fairly typical. It has a rotating glass dish in the bottom. Since the Pyrex dish is a rectangle and is too large to turn in circles, I set it with one end on the rotating plate and the other side hanging over the edge. This helps to prevent a lot of excess movement.

The cooking time is 2 minutes, then open the door and turn the dish around so that the other end is toward the center. (I do this so that the heat is more even.) Then 2 more minutes and turn again. Repeat this until the fiber has had 8 minutes total in the microwave. If you are worried about your color, you can check your roving after 4 minutes. Just be sure to wear those gloves to protect your hands from the dye and the heat!

Allow your hemp to sit in the Pyrex dish until it has cooled
completely. Then rinse your fiber with cool water until the water runs clear. Squeeze out the excess water and lay your roving out on a towel to dry in the sun or hang it over the shower rail if the weather is not cooperating.

When your fiber is dry, it may feel a little stiff. If you gently pull on the roving in the same manner as if you were drafting, The fibers will loosen and feel softer.

That's all there is to it!

No comments: