Wool is an amazing material: it wicks moisture and keeps you warm even when wet. Felting the wool makes the material even stronger and more durable! Felted slippers are simply awesome for wearing around the house!
But just like any fabric, it will wear thin over time. To lengthen the life of the slippers, I think its imperative that some reinforcement is added to the soles. This is how I did it for my slipper design:
I bought a few yards of this Jiffy Grip fabric (what is on the bottom of kids' footed pajamas) for $6 a yard from Joggles.com. I usually like making the soles of my slippers in a contrasting color, so I really wanted to make the no-slip pads as small and shapely as I could so they wouldn't detract from the colors of my slippers.
I traced the bottom of a slipper onto the fabric to get a rough shape to begin with. I continued trimming the pad down until I got the size and shape I was looking for. The pad covers all the hard wear spots of your foot without covering the entire sole. An L shaped pad for the ball of the foot, and a small pad for the heel:
I then generously cover the pads with a silicone caulk. This helps thicken, strengthen, and adhere the pad to the felted wool. I've seen people smear silicone sealant directly to the bottom of their slipper to act as the non-slip surface. I believe this would work fine, but it looks messy and unfinished to me.
I squish the pads to the slipper sole in the right spots and let the silicone set for 24 hours. I then hand stitch the pads to the slipper. This takes me about 1 hour per slipper! But I really think its important. Yes, the silicone will keep the pads on, but without the stitching, I believe that over time the edges will peel up and be unsightly, and cause you to trip.
Mending a hole in your slipper using roving and a felting needle:
Put one layer of roving on the outside of the hole and a foam pad on the inside of the slipper. Needle felt this layer, then add a second layer of roving perpendicular to the first layer and continue felting with the needle. Turn the slipper inside out and repeat these steps to felt roving to the inside of the hole. This will re-thicken the slipper in the damaged area so that when you put the non-slip pad on, there won't be a cold or thin spot where the hole once was.
This slipper has a hot spot that needs mending.
The light brown roving on this slipper still needs a bit more felting before being covered with the no-slip pad. The roving won't be visible when the slipper is finished.
