I have never seen that construction. Usually a ruana is two long rectangles, sewn together halfway and with no neckhole. (in the olden days a loom created fabric no more than 27" wide because that's the distance a human could work comfortably)
Can you create your own pattern based on the wearer's measurements?
For the back your width would be elbow to elbow and your length would be shoulder to knee.
Each front would be that length and half the width.
Can you create your own pattern based on the wearer's measurements?
For the back your width would be elbow to elbow and your length would be shoulder to knee.
Each front would be that length and half the width.