This I'm not sure of - not experienced much as a felter I've only done one project so far.
4. what are the best felting yarns out there?
Again - someone else can perhaps help a bit more here - I'm not that experienced but I did use a discontinued Wendy Tweed wool for my Lucy Bag (see my blog - not myspace for details).
The Felting Process:
1. Is there a way to predict/know how much the item will shrink? Some kind of formula or something?
Felting can take several goes to get it to the desired size. My Lucy bag shrank to a decent size when I did it with one wash at 95 degrees. I have front loading machines here in the UK so it's not as easy as felt it for a bit take it out have a look put it back.
2. Does it create lots of lint in the washing machine?
I didn't find any / much lint at all in my washing machine after felting Lucy - I suspect with repeated use though it might become a problem but I'm not sure. Perhaps a more experienced felter could respond here?
__________________ My Space My Blog
Disclaimer: I'm not responsible for anything saucy or cheeky on those links... well, not much
mohair and angora will felt, as will alpaca and llama. i don't think silk would. i have seen patterns with a combo of 2 strands, one of wool and one of angora, and also using a substitute yarn that was not 100% anything for the angora strand (it was something like 75% mohair, 15% wool and 15% nylon).
anything labeled superwash will not felt and white or other bleached shades generally will not felt due to the chemicals that it's been processed with.
jeans work better than towels for the agitation, they don't lint (even ancient towels seem to shed!) and a zippered pillow cover is your best bet for keeping the wool (or whatever) bits to itself, not in your washer pump. you can also use a mesh bag but may have some smaller escaping fuzzies; a knotted pillowcase works in a pinch also but is hard to keep knotting and unknotting as you check progress. i think the loose lint from the project doesn't show up much in your washer basket, but rather in your pump, and will eventually wear it out - the zippered pillow cover is a tighter weave than the mesh bags and should keep everything within the bag (although i usually don't have much project lint anyway).
i've had good luck with noro and paton's merino wools.
if you're following a pattern and using the yarn specified, you just need to get gauge and then follow instructions. if you are winging a pattern or substituting yarns, you would want to make a swatch, measure it, felt it and then remeasure once it's air dried to get your percentage of shrinkage in both directions.