Felting is the textile term describing the process of shrinking untreated, sheep’s wool (hair fibers), which results in a dense, matte fabric. In textile manufacturing, the process of creating felted fabric using knit or woven textiles is known as “fulling”. It is commonly referred to as “felting” amongst crafters.
At one time or another, you may have shrunk a wool sweater by accident in the washing machine. The cause of felting is due to the nature of wool fibers. Like human hair, wool is a hair fiber composed of scales along its surface. When these scales are exposed to heat, moisture, and agitation or friction the scales entangle, and the fibers shrink and matte. This process is irreversible. Note: Superwash wool has been treated to prevent shrinkage, so that items can be safely laundered in the washing machine without felting. You want to make sure when felting that you use natural wool.
Felted fabric is produced by textile manufacturers to make dense fabrics such as boiled wool and melton. At home, the washing machine is used to make felt projects from hand knit fabric. Needlefelt is another felting procedure using unspun fibers (roving) and barbed needles. This technique is better used for creating sculpted shapes. Hand felting fabrics is possible, but is more time consuming.
The project must be knitted much larger prior to felting. If designing a felted item, or using a commercial pattern, experiment with an extra large swatch noting the gauge prior to felting. Felt the swatch as described below, noting the time needed to get the desired look, as well as the final measurement of this swatch. This test swatch provides important information, the approximate shrinkage, and the numbers required to calculate what the measurements of your pieces need to be prior to felting. Felting is best performed on 100% wool fibers. Other hair fibers felt, but not as beautifully as wool.
Usually pieces are sewn together with the yarn used to knit the item before felting, as it is difficult to hand sew seams in knit felt, or weave in yarn ends. It might be necessary for items like bags to sew the top edges loosely together with a synthetic yarn (one that doesn’t felt) to prevent losing its shape.
Top Loading Washing Machine (agitating mechanism in the centre)
The agitation needed for felting is provided by the back and forth motion of the middle section of a top loader. What is great about using this machine for felting is you can easily spot check your project to see how it is progressing, by lifting the lid and pulling an item out. A top loader is recommended, because it provides the necessary agitation.
Felting procedure: Place the finished item in a laundry bag or pillow case, to prevent excess lint in the washing machine. Set the machine at a low water level or small load, normal cycle, to a hot wash and cold rinse. Add a very small amount of detergent like Woolite or Eucalan, and run through the cycle (soap is not important to the felting process). Using your swatch as a guide, check the progress every five minutes to make sure the item is felting to the desired effect. You might have to repeat the cycle, and it may be necessary to add an old towel or worn out jeans for additional friction. Some people prefer felted fabric to have no stitch definition. When you have achieved the look you want, rinse in cold water. Dry flat, shaping the pieces to the recommended size. Note: Felted fabric can be cut without the risk of unraveling.
Front Loading Washing Machine
Although a top loader does a better job, it’s possible to felt in a front loader, but a few adjustments are necessary to successfully felt.
The agitation in a front loader is caused by rotation of the drum. The items are dropped from top to bottom of the drum repeatedly through the washing cycle. The beauty of front loaders is that the tumbling action is gentler on clothing, but is not as efficient for felting as a top loader.
Another difference from the top loader is a front loader usually locks shut during a cycle, so you won’t be able to open the door and check on your project. Some front loaders allow you to stop the cycle, but the machine will drain first before you can open it, and the machine will not continue from this point in the cycle.
To felt in a front loader, follow the same steps as above for a top loader, but add items for additional friction. Carefully test your swatch, keeping to gauge, writing down all measurements pre and post felting, and the time it takes to obtain the look you want. Do exactly the same process with your project as you did with your swatch – same yarn, needle size, and wash cycle. Remember that if your machine does not allow you to open mid cycle, you have no choice but to finish the cycle. Because a front loader is gentler, felting will most likely take a full cycle to achieve the desired effect.
Felting hand knits is a lot of fun. I knit a couple of bags to felt from Ella Rae’s Book 11 (Fourteen Exquisite Designer Bags to Knit and Felt). If you love hand bags and felting, this book from 2008 has some of the best designs. Felting is an enjoyable process when done “deliberately”.