(This text originally appeared on my blog.)
In a perfect world, every skein of yarn is a perfectly arranged series of loops, ready to be unwound with no trouble whatsoever.
Unfortunately, this is not a perfect world, and after going through the rigors of a dyebath or after being mangled by children, cats or other calamities, you might end up with a tangled skein. Maybe even a severely tangled skein.
You have three options now. Option One: Throw that lump of loops into the rubbish bin. Yes, that is a valid option – if you don’t really need that yarn, if you can buy it again, if you don’t have a lot of patience, if you are not really willing to untangle it, if it’s wool and has felted itself together in the tangling process, so that pulling apart the loops will damage the yarn. If it’s one-of-a-kind or it was horrendously expensive, though, you might not want to throw it away. Luckily, there is Option Two: Figure out some way to use the yarn that does not require it to be all in one piece. Draw out as much yarn as possible at one time (or your pre-defined lengths), cut, untangle the knob that forms, repeat until skein is gone and you are left with a number of one-length cutoffs. Take care to wind each cutoff after measuring it and cutting it, or you might face more tangles!
That is not the thing you need? You really want one long length of yarn? Then take a deep breath, go buy some chocolate, put on a kettle for some tea and sit down for some lengthy yarn skein de-tangling. To get an estimation of how long it will take you, make a wild guess. Then multiply the time of your wild guess by two – that’s the pessimistic wild guess. Now multiply that by ten, and you have an estimate. (Seriously, if you are pressed for time, this is not an option. Go buy another bit of yarn. And if you are not patient in the face of tangles, find somebody who likes to untangle yarn and bribe that person.)