Ah, I assumed you were a kiltmaker.

Steeking is Gaelic for "to stitch". It referrs to a line of stitches which hold the pleats in alignment. In a Traditional Kilt the pleats are cut away in the Fell and need something to hold them in place. The Steeking is done from the inside and is not seen. In a Contemporary, machine sewn Kilt the steeking will show up as a line of stitches at the bottom of the Fell.

Without a Steeking line the pleats will wander and splay due to their own weight. Especially when using light weight Cottons.

Skip the Steeking at your peril.