I first saw this work at a antique quilt exhibition in France. At that point I didn't know about the French quilting tradition, then I saw this post from http://www.facilececile.com/archives/2020/10/04/38569302.html .
Now I have been playing around with the technique. In Cecile's post she also had a link to the same quilts that I had seen and says that the tin templates that were used were sold by pedlars and could sometimes be found in Secondhand Shops. She made her template from cardboard. There is also a mention of these tin templates being sold in the USA and they sometimes come up in antique auctions. There is another very good tutorial at Knitting-and.com. This tutorial has a link to a PDF file of templates.
Looking at those old quilts I realised that they are all made on a wool or wool felt fabric. I then found some woollen fabric left over from a tweed skirt I had made. As it turns out this was a good choice because the weave isn't super tight and it is easier to pull the woollen thread through when stitching. Having said this I believe that any fabric that has an open weave should work with this technique. But, it is still quite hard work on your wrists, mine were a bit sore by the time I had finished.
The other difference was the wool I used. I had bought a bag of tapestry wool from the 2nd hand stall at the Guild which only cost $10.00.
When I looked at Cecile's post I see she was using wool used in crewel work which is a lot thinner than the tapestry variety so there was going to be a different outcome, but not quite a much as I had imagined.
This is Cecile's who has also worked on a wool fabric.
This is mine. I tried to keep the stitching the same as hers but I think that if I had used a third colour layer, that would have covered that slight gap you can see.
The different wool used does affect the finished piece. I wish I had taken some close up photos of the original quilts but I think that they would have used what ever wool they had to hand so there would have been a difference here as well. This technique used left over or repurposed wool and fabrics originally and these would have been classed as scrap quilts as beautiful as they are.
I was reading in one tutorial that you should mount your work in a hoop. Not possible with small scraps of fabric but I will mount another piece of wool fabric in a halo and see what the difference is. I might try some different shapes but because of the strain on my wrist and time involved in the stitching I can't see this becoming a major technique for me. Still it was a fun exercise.
Now what am I going to do with all that wool?