The absolute minimum is the overall length of the kilt from the top edge to the bottom. Most kilts are in the range of 22-25". You'd have to be pretty tall to need a kilt longer than that. A kiltmaker typically uses the strip cut off from the selvedge edge to make the top band so that the tartan can be matched across the apron, so a kiltmaker uses more like 25-28" of width. But, that's not really necessary if you have a bare minimum of width. You can always piece a bunch of weft-wise strips if you absolutely have to. Your belt will cover the top band seam anyway.

The only way I know of to weave a double width on a hand loom is to double the ppi and set up the loom so that you weave the top half of the cloth on one pass and the bottom half on the other, with the weft thread turning and going back at the fabric midpoint. It's complicated, but it can be done. That's a lot of threads per inch, though, and the web will be _really heavy_.

Barb