The recommended yarn yields a highly-textured lace pattern and this might not be the case with other fingering-weight yarns - although they certainly could be substituted for an accessory of similar size.

I used two skeins (with about two-thirds of the second skein left over) of Eden Cottage Yarns Brimham High Twist in Silver Birch. There would be sufficient yarn to add additional repeats for a longer scarf.