I used some old recycled yarn that was bought many years ago and used to be a sweater, then - a cardigan, then - a dress (see the pictures). I unraveled it last summer (described the process here and finished up making a blanket/throw/coverlet out of it. I knit till ran out of yarn. The finished project is almost a square: 46” x 46.5”.
The pattern is not easy - you need to pay attention and count stitches in every row. Plus the rows were long - 139 stitches. Often I would fall asleep in a middle of a row, loose count, make a mistake, unravel, and start over. That’s why it took me almost a month to finish this blanket my main motivation being never getting back to this yarn. Mission accomplished:)