There is no set rules with felting a wall hanging. What I mean is, that some prefer a very loose felt while others want a very tight felt. I have seen some which were felted very loose. And again, depending if you used a coarser wool, it will not look as sleek as mine. For this reason I use Merino wool. But I am not saying that an other wool would not look as good. It will just look and feel different.

If the wool is coarse it will in general look more hairy. Because thicker hair finds it harder to connect with each other.

In the end, when I feel I have felted and fuelled the wool enough. I wash out all the sod from the soap. Rinse it a few times. Either in a big bowl or under a tap. Whatever works for you.

Then I always add a dash of cheap vinegar to the last rinse. And I leave the vinegar rinse in the wool. I don't rinse it out again. Vinegar will help to neutralize the soap which may be left in the wool and it helps to bring back the natural pH of the wool again. Vinegar in short will protect the wool. The wool will not smell as the vinegar is well diluted with water.

I always tell students during my courses that wool is no different then your own hair. If you leave shampoo in your own hair. Over time your hair will loose its shine and start to beak, looking dull. Wool from any animal is no different in that regard.

This is a picture of the wadding that I use for the back. I use 5 mm thick wadding. You can buy this in all good fabric shops. It comes in different thicknesses.

If you use a thicker wadding, your sewing machine might struggle to stitch it.

After the felt has dried. I am adding a wadding to the back of the felt.

There are two reasons why I do this.

First and most important, I want to protect my sewing machine. When I start to stitch with the sewing machine, I get a lot of dust from the felt (wool). All this fluff will fall down and into the body of my sewing machine. The wadding will protect the sewing machine from this.

The second reason is the 3D element I get from wadding. It will plump up the felt around the stitches. Which I rather like. You see the difference in the next picture. The purple example.