20 metres is about 65ft - which, if it is double width would mean six kilts, about 7 yarders to me -

Or maybe a box pleated kilt, two 'full' kilts, one pleated to the sett and another pleated to a stripe and still three good kilt lengths left.

I have quite a few pieces of non tartan fabric where I have bought a bolt and then taken the kilt lengths all in one rather than cutting 54 or 60 inch fabric in half. It is a luxury not to have to piece together fabric to get the length required, so I have done it a couple of times now.

I think if I put all my fabrics together it would be frightening - not the cost of it, just the danger of avalanches.