Stylecraft Kon-Tiki has been a popular yarn in Stitching Time ever since it was introduced. It is lovely knitted up for childen and for adults.
It costs only £1.89 for a 50g ball with 101m. The recommended needle size is 4mm with a tension of 22 stitches and 30 rows to 10cm.
It has a 50% cotton/50% acrylic mix and is machine washable.
If you aren't faint-hearted, here is Nan wearing a top she knitted with this yarn.
The pattern was in the 'People's Friend' last month so it is not commercially available. However, if you ask nicely, she might let you 'borrow' it.