Curtain twine

The curtains for the bedroom have buttonholes across their tops. I've been thinking about what to use for rings or ties.  Yesterday, while looking for something else, I came across some natural-fiber twine, dyed green, that I picked up at a rummage sale years and years ago, and then never found a good use for. I cut the twine into identical lengths quickly by wrapping it around a book of the right height, and then cutting across. I strung each length through a buttonhole and knotted it. I discovered that the curtain rods would extend a good distance wider than the windows, which I wanted. The curtains are also much longer than the windows, and are now a dominant feature in the room. I am now thinking about whether or not to line the curtains, which are somewhat loosely woven. I have a spare white sheet, but it is not opaque enough, so I think I will use that (in a double layer) for a clothing project instead...I've reached the stage of pregnancy where I'm getting tired of wearing my clothes that still fit.