Anna let me borrow her massive book by U.T. Sirelius titled Finlands Ryor - Textilhistorisk undersökning. It was printed in 1924 and gives the history of ryijys dating back to 1495 to 1870. It's in Swedish so I'm letting the images take the lead. Feeling breathless by these knots!!
U.T. SIRELIUS, KIRJA, "Finlands Ryor - Textilhistorisk undersökning", Kustannusosakeyhtiö Otava, Helsinki 1924, s. 37.
Arlene Tucker is currently based in Helsinki, Finland.