i shop thrift stores for wool all the time for wool projects- it does not have to be a merino sweater- men's wool suit coats, skirts, trousers...all felt wonderfully! i always check tags at thrift stores & yardsales...as long as it says 100% wool you can use it.
visit Sue Spargo's web site for inspiration & great ideas for using wools. also Seasport Hooking, Primative Gardens, the Cotton Patch Quilt Shoppe (in East Tawas, MI) many places are carrying patterns for felted wool applique projects---here's what i've been doing with mine lately...

It's getting harder to find 100% wool. Most suits are a wool blend now. About five years ago I found a shop that had wool fat quarters on clearance. The shop was not selling that line anymore. It was Sue Spargo wool fabric. Even at the clearance price it wasn't selling very fast. The shop owner said if I would buy the complete bundles she would take 75% off the clearance price. Heck yeah! I got four fat quarters of every color and bags of wool strips used for wool rug hooking and have it stored in a big bin waiting for me to get inspired. LOL
98% of my stash has come from clearance sales and going out of business sales. I search for these sales like searching for gold. I have given a lot of the wool fat quarters away to members on this board.

This washed wool makes great purses! They are so durable and cute.

I tried this with a wool sweater I bought at a garage sale. The problem was I have a new "energy efficient" washer. It never get hot enough to shrink the wool:-( The good news is my t-shirts and other clothes don't shrink in the wash either. A friend told me I could boil the sweater on the stove, but I need to keep stirring it because the motion helps the wool to shrink. One of these days I'm going to try it.

My best wool find was a "Woolrich" brand gathered,calf length skirt in tiny red and black check. I paid $3 for it, felted it and had probably 4-5 yards!! I used some to line a fireplace mantel scarf for Christmas and gave a friend some for Santa's hat on several candle mats! I purchased it at goodwil. I have also cut apart a couple wool coats I no longer wore. I would love to find a white long wool coat at thrift store to felt and dye.

I have done alot of "Salvation Army" shopping for wool that I felt. The sweaters make great hats, mittens, purses. I use more of the clothing wool that I felt and then do lots of wool applique. Buying wool in regular/specialty stores is very expensive. Last summer I stumbled on an add for a rug hooker garage sale-got lots of great small pieces in huge amounts of color variety. Most of them came in groups of 5-6 pieces of wool in subtle shades of the same color-they were orginally priced at about $8.00 each set. I paid 50cents for each set and the sets had been boughten years ago and now you would definitely pay alot more for them than $8. I also got some big pieces of wool for 50 cents each. Wool that would run about $25-$30 a yard. What I am saying is look around and keep an open mind and you just might find wool at prices anyone can afford. Enjoy using wool-I love it.
Kat

Very nice projects! Thanks for the tips on felting, too. This is all very new to me, but I am having fun finding out about it. My mom and I are looking for things we can do together, since she can't really quilt any more due to the tremor she has developed in her hands. At 87, she has been doing very well, but just can't control pieces well enough to use a sewing machine. She can do hand sewing, though, and is enjoying doing some embroidery. I think she will really enjoy doing stitching on some felted wool projects.

And that is on my "to do" list for the wool, too. I saw a really cute bag with an embellished wool panel, and it was so adorable!

Yes, it's agitation as well as heat and detergent that cause the felting.

I'll have to try some mug rugs. I became obsessed with thrift store wool sweaters a few years ago when I was making mittens out of them. Some were already quite felted, probably why they were at the store in the first place. But some, oh my, some were gorgeous sweaters and it was SO hard to throw them into the washing machine.

For those who had trouble felting in the new energy efficient machines. Yes, it does help to have lots of water but what really felts them is agitation and temperature shock. WAsh in hot, rinse in cold, dry on hot. My washing machine is HE. And some sweaters, even pure wool, just take more than one go round of that brutal treatment.

If your washing machine doesn't get hot at all there must be something set up wrong with it or maybe you have an anti-scald valve affecting it? After all, you do sometimes need to do a hot wash.

If you try mittens as I did, the lint really bungs up your sewing machine. It's not great for your washer and dryer either. Yes, I did a lot of them.