Best rags for oil painting? (and maybe other painting?)

This is going to be completely subjective, which is awesome because I love hearing different ideas on this sort of thing.

Gor those who missed it, we've got a great thread on what to do with those oily rags.  

So what kind of rags do like for painting?  What qualities do you look for?  Where do you get them?  

My least favourite so far is paper towel for oil painting.  It doesn't seem to last very long or hold much oil.

Whereas old, worn out (not new) cotton or mostly-cotton sheets seem to do the best for oil painting so far.  One small rag will last a painting or two.

The issue is, I have to tear up the rags, and it takes forever.  I get the most worn bedsheets from the thrift store.  If I am having a smart day, wash them.  Then make little snips and tear them to smaller rags.  This takes ages.  But I only have to do it few times a year.  

The only other thing is they get a bit of lint on the brush which gets on the painting.  

...

for watercolour, I like paper towels best.  If I dry them out between paintings, they start to behave like new the next time and one or two small squares can last many many paintings before becoming too full of paint.  

Old cotton tshirts are my go-to. Not all that much lint and pretty absorbent. Plus I get bonus nostalgia points when I see the band logo or concert dates and remember the gig. Or the one that I got in the early '90s that said THE INTERNET IS FULL. GO AWAY.

In my kitchen, I use cotton bar 'mop' towels in lieu of paper towels for most things. I have been known to ruin a few by redirecting them to my art room. But they do a good job, and I've started taking the towels that are getting raggedy and adding them to my stash in the art room. But my favorite thing to use is the supposedly disposable blue oil rag towels on a roll in that I find in the auto department at stores. They're more of a cloth than a paper towel, don't give up lint, and are very absorbent and can be washed several times. I rarely use solvents in my oil practice, so none of my towels last all that long because it's hard to get the paints out of them without the chemicals, but if I wash them with old cooking oil first, then with dawn dish soap, they last a bit longer.

I have a large stash of thrifted/auctioned fine linen tablecloths and napkins. They were all cheap and most have at least some stains. ( cheap to get as old. They were all pricey when new)
I've made a few clothing items out of some and cut around the stained areas. I still keep those bits, if the pieces are large enough, and they become rags and cleaning cloths.
They are amazing art cloths. Soft, smooth, absorbent and lint free!  I also don't feel any pangs about using them up and throwing them when they are full up since they have had a long chain of use.