Lace is sometimes considered the pinnacle of knitting, because of its complexity and because woven fabrics cannot easily be made to have holes.
From there, knitting patterns for the shawls were printed in English women's magazines, and they were copied in Iceland with single ply wool.
Knitted lace with no bound-off edges is extremely elastic, deforming easily to fit whatever it is draped on.
A hole can be introduced into a knitted fabric by pairing a yarn over stitch with a nearby (usually adjacent) decrease.
It is common for lace knitters to insert a "lifeline", a strand of contrasting yarn threaded through stitches on the needle, at the end of every pattern repeat or after a certain number of rows.