The sample felted well too using the muka and whiitau from the Flax Mill in Foxton.
I made a template of 150 x 150 mm and laid 2 layers of polwarth wool in oppposite directions each layer. i felted it and fulled and my shrinkage rate worked out at 28.5%. It shrunk more in one direction as i did not pay too much attention to the way I was rolling it and rooled more in one directio. Wool shinks more in the direction of the rolling friction.