Click here for the printable Twig + Tale Boot Size Chart for measuring your child's foot.
Exterior: I like to use wool cut from recycled felted sweaters (one which has shrunk after going through a hot wash for example) or soft woolen blankets. If the sweater is not felted, you may find the wool stretches as you sew it, which makes it tricky - especially when sewing it onto the sole. Felted sweaters can be thick, so you may need to go up a size. Instructions on how to felt sweaters are below.
You could also use a wool fabric, wool blends, denim, cord or other fabric with reasonable structure. A softer fabric such as fleece will create a more slouchy boot.
Lining: Cotton, linen, flannel or other breathable fabric.
Insoles: Wool from a felted woolen sweater or blanket.
Soles: Leather or suede - I use an old skirt or jacket from the thrift store. You could use corduroy or denim for non-walkers.
One sweater is generally enough to make a pair of boots in the baby or child sizes. You may need to mix and match two sweaters if making the youth sizes. If purchasing fabric, you will need a 1/4 yard (or metre) of fabric for both the exterior and the lining.
To start with, you need to source a sweater made from natural animal fibres, such as wool, mohair, cashmere, angora, or merino wool. Check that the percentage of natural fibres is at least 80% - otherwise it will not felt. “Superwash” or "machine-washable wool" will not felt.
Wash your sweater on a HOT wash using a regular laundry powder. You do not want to use a gentle wool cycle or wool detergent as they are designed NOT to felt your wool! You may need to put it through a hot wash twice. If you have a dryer, that will also help felt your sweater. Use the hottest setting.