making a felt mat from used woolen sweaters

Hello, I would like to use used woolen sweaers to make a matt for yoga class. Looking for a warm alternative to the petroleum based matt. Would you know some tuto for this ? Thank you.

I think it depends on the sweaters, which would have to be entirely wool, and not the 'superwash' or washing machine safe type. Do you already have them? How many, and how big are they? The bigger they are, the less piecing you'll need to do - unless you want to do more piecing.

I'd start by washing them once in warm water - not hot, yet, to full them enough to ensure they don't unravel, when you start cutting. Then, I'd probably cut and piece them to about 25% or so bigger than you want your finished mat. You've a few options in how you join the pieces: butting the edges, you can whip stitch by hand, overlock (if you've that type of machine), or even zigzag(though this would be the most likely to pull apart, in the stress of use). If you want to machine stitch, overlapping would work, but I'd strongly recommend zigzagging or overlocking both edges; or you could needle felt them, though this would take the most time, if you're going to do it with enough strength to actually hold together without any stitching. Another option would be Japanese style sashiko or Boro stitching, or Indian Kantha quilt style stitching.

Since the mat will shrink more, in the wash, you'll want to stitch fairly snug, but not super tight, because the mat will thicken, as it shrinks. If you really want to have some fun with it, you could also add some decorative embroidery, crazy-quilt style. Or add a longer, narrow pocket to roll the whole thing up into, or a different pocket, a bit more square, to fold it into, to create a cushion... the possibilities are only limited by your imagination. My only concern is the non-slip characteristics of a regular mat won't be there, in the wool, so it would be wise to keep that in mind, in your yoga practice.

Thank you, Carla for your answer. I kept some wornout sweaters for that project (5 large ones) but I'm not sure about the % of wool they have - would any % of synthetic fiber make it unfeltable ? Thanks for the info on the japanese an indian kantha stitching ! I did not know the name kantha but I surely know the stitch even if I never practised it. As for the japanese stitches,  I did not know them uch as I'm not very familiar with japanese textile but they are really lovely ! Actually I'm not practising yoga for the moment but do-in, but an exercise mat is an exercise mat... but you are right about non slip quality - maybe coton material on one side would help ?

Cotton will likely be just as slippery, on the floor, I'm afraid. But, I've been thinking about this conundrum, quite a bit, because while I'm not allergic to natural latex, I'm highly allergic to adhesives. Ok, what's the connection, right? One recent night of insomnia, an idea popped into my head, that I've not yet had a chance to try, but... I *think* it ought to work for my allergy problem(I can't use medical tape, bandages, etc), and when thinking about your mat, it occurred to me, it might work in this application, too.

Have you seen the beeswax food wraps? My theory is that a few smallish ones, say 6" - 8"squared, strategically sewn to the bottom of your mat ought to do the trick!

There is the slippery aspect on the floor and in contact with our feet. Anyway when I wear socks for practice (in the winter) it is slippery on a foam mat too. I'd say flannel cotton is less slippery than others or maybe not at all ? Beewax patches would be a good idea - thanks !