Heat, moisture and friction are the three main elements needed for felting. The felting process entails matting loose fibres together to form a solid piece of fabric. One of the most common fibres used for felting is wool. Sheep naturally make lanolin, which protects the wool from moisture and heat. Other animal fibres such as alpaca and llama share the same properties for making the fibres feltable. Designers use different methods to felt fibres, such as wet and needle felting.
One of the most common ways to measure the wool is by the thickness, referred to as the micron count. The thickness of the wool determines the amount of time required to felt. According to "Felting: The Complete Guide," author Jane Davis writes, "A good rule of thumb is that the finer the fibre, the more quickly it will felt." Another method used to measure the wool is by calculating the number of yards of yarn spun out of a pound of wool, referred to as a spinning count or the Bradford count. Merino wool, generally sold at arts and craft stores for felting, often has a micron count of 24 to 28.
Although arts and craft stores sell felting kits, you can also purchase wool, sold in three forms: worsted preparation, woollen preparation and locks. Worsted preparation refers to combed fibres, with short fibres separated and removed, leaving only same length fibres. These fibres tangle together as the same length fibres cross over each other in different directions. Woollen preparation refers to carded fibres, which retain the short fibres. This wool form is popular with needle felting. Locks refer to cut and washed wool, making locks remain intact. Use this form as felt accent pieces.
Placing the wool form on a padded surface or a needle-felting mat protects you from needle pokes and the table from damage. Felting needles have small barbs along the length and are generally triangular or diamond-shafted. Be extra cautious when handling the three- or four-sided needles because the barbs are sharp and brittle. Inserting the needles into felting needle holders alleviates your hand while needling the fibres, forcing the fibres to tangle together. If you choose to hold the wool form in one hand while needling, wear a leather-crafting glove.
Saturating wool fibres in warm, soapy water is the first step for wet felting. Pat down the web fibres with your hand to compact the wool. This process allows you to see how thin or thick the wool is and gives you the opportunity to add more wool if desired. As the water cools and the scales of the fibres start to close, the tangled fibres lock together to form the felt, referred to as agitation. Once the fibres have intertwined, the shrinking process takes place, referred to as fulling. Designers working with felt also add embellishments during the wet felting process such as yarn or small pieces of fabric. A thin layer of fibre embeds the added components into the felt to create a one-of-a-kind piece.