When my mother started making pitsi, she got only age old plueprints of the models with numerous errors. She and my father worked long evenings remaking tens or even hundreds of models on a better paper. In the old days most of the models were drawn on normal paper. My father started to use pertinax, impregnated thick paper that lasted better. Nowaday it seems to be standard. I thing they were one of the pioners to start this work even they didn't want to make noise of it.
First my mother used old fashioned tools making pitsi, but my father saw some difficulties (even stupidities) there and made a new model. After some ten years about every women had copied my fathers model. After that there has still been modifications.
I don't mean that my parents were the only ones. There were many interested and enthusiastic woman and man in Rauma those days. You better check there yourself
Here is an example of My mothers Rauman pitsi scanned by a cheap 300x300 table scanner. I made it in 'white on black' and 'black on white' so you can print it out better. (Click the picture, 377kB)