Curtains for 17th Century Farmhouse (saye or serica?)

Hi Everybody, I need some help! I'm a fledgling interior designer in need of advice re curtains for a 17th Century farmhouse sitting room. I believe the material used in this era was either saye or the more expensive serica (Latin for silk - I looked it up), but can find very little information and hardly any images. The ceilings are low and beamed, so not sure whether to choose short or long curtains. I'd like to know whether the material would have been plain or patterned and likely colours. All knowledge would be gratefully received!