I've been making felted stones for several years now and I've often been asked how I make them. There are different ways of making stones, but this is my method, one I've tweaked over time to suit me.
Want to give it a try?
What you'll need:
a felting needle
an old clean towel
soap (I use dish soap)
a plastic bag
access to hot and cold water
To start, fluff out your roving and pull wisps of it off. Lay these wisps down with the fibers laying in the same direction, slightly overlapping, until you have a mat of fibers forming on the table.
The mat should be slightly wider and roughly 3 times longer than the stone.
Be sure that the first layer of wool is of a consistent depth and there are no large gaps in the mat. The bottom of this layer will be what you see on the outside of your finished stone so it should be as uniform as possible.
Add a second layer of wool with the fibers laying perpendicular to the first layer.
Press down on the mat you've made. If you can feel gaps or if the mat feels unusually thin, add a third layer, again running perpendicular to the layer beneath it.
Lay your stone on the fiber mat. If your stone has a definite top and bottom, position it with the bottom side up. Fold the wool up and over the stone and roll the stone over one time, keeping the wool taut as you roll.
After this first fold, the top of your rock should be facing you.
Fold the side pieces up and over the top of the rock. These sides will pad the top of the stone, giving it a slightly thicker surface than the bottom. This helps the stone sit nicely once felted.
Continue rolling the rest of the wool over the rock, keeping the wool taut but not so tight that you pull fibers out of the mat.
If you don't have a felting needle, you could take the stone right to wet-felting at this point. If you do have a needle, even out the fiber at each end of the stone until you can no longer see where the fiber was rolled.
Fill your bowl with hot water and add a drop or two of soap. Dribble water over the stone gently until all of the wool is wet.
Carefully move the wet stone from one hand to the next, sort of like you're playing catch. You want to treat it gingerly until the wool fibers start to pull together.
Dip the stone back in the water from time to time to keep the wool warm. You can also add a drop of soap to your hands as needed and keep rolling the stone gently. Once the wool starts to hold together a bit, you can start to add a little more pressure. You'll want to be careful not to rough up the surface of the stone, but rather to get those fibers to bind together around the stone.
Once the wool has felted around the stone pretty securely (if you can pinch the wool and separate fibers from the mat, it's not ready yet, keep working) grab your plastic bag.
If the bag has a logo printed on it, make sure to turn this to the inside so the ink doesn't transfer to your stone. Wet the bag, fold the stone up inside it, and rub. This is where you can add some real pressure to the stone. The tiny folds in the plastic bag act as a gentle washboard but the smooth surface keeps the wool from getting scruffy. Rub and roll the stone with the bag until the wool is firmly felted.
Immediately rinse the stone under very cold water (or dip it in a bowl of ice water) while rubbing it with the plastic bag. This will help the fibers lay down nicely.
Lay the wet stone on the towel and leave it to dry. Don't try to force water out of it with a towel, just leave it alone. It's a good idea to use an old towel or a rag as some dyed rovings can leach some color while drying and you wouldn't want that on your pretty tea towels.
Once your stone is completely dry, you can trim off any stray fuzz with a pair of scissors.
And there you have it! A stone cocooned in soft wool. Oh the possibilities.
Do keep in mind that some wool felts better than others. Roving marked "superwash" isn't going to wet-felt for you. Sometimes undyed wool can be harder to felt as well. Some wools like shetland have a scruffier surface. My favorite wools to use for this are corriedale, falkland, polwarth, and merino but experiment and see what works for you.
If you have any questions, please ask them in the comment section and I'll answer them there too.