Wet felting is the process of taking layers of carded wool (typically comes in batts or roving) and applying hot, soapy water and friction to them, which shrinks and interlocks the fibers creating felt (in our case, a ball).
We purchased pre-dyed packages of 100% wool roving at our local craft store. Wool roving comes in a variety of colors that you could select. The only other supplies you need are hot water, dish soap, a container to hold the hot soapy water, and your hands!
Fill your container (we used a large plastic tub that was big enough for all of us to use) with hot water, and add about one tablespoon of dish soap to create a sudsy mixture. The wool will felt best in hot water, but make sure you don't get it too hot for your (or your little ones') hands.
Pull off a small section of the wool roving for each ball you would like to make. Take a section of roving and pull at it to loosen the fibers, then shape it into a "loose" ball. If you are interested in having multiple colors in your wool balls, this is the time that you would want to have your second or even third color of wool roving ready. Gently wrap the additional color(s) of roving around the ball. It does not need to be super tight - once you get the wool wet, it will begin to blend together.
Next, dip the wool roving ball into the hot, soapy water and begin to gently shape it using the palms of your hands (similar to how you would roll play-dough when you want to make a ball). Be careful not to press and roll too hard. Continue dipping the wool roving ball into the hot, soapy water and rolling it in your hands with a circular motion, making sure that it stays a nice round shape. You will begin to feel the wool become denser and denser as you roll.
After the balls are fully felted, you will want to rinse them carefully to remove the soap from the wool. It takes roughly 24 hours for the wool to try. We just placed them on a plate and laid them on the counter top. When they are completely dry you can make necklaces, bracelets and hair accessories. Have fun!