Wondering around the Internet to give my hand a rest from this morning's knitting, I came across a really simple but effective aid for planning Fair Isle designs: A web page that will produce a PDF of squared (graph) paper to match the tension of your intended yarn. Enter the number of stitches and rows achieved from your swatch and off you go. An excellent idea. Meanwhile, I'm wondering whether I'm starting RSI :-((
Find the "Actual Size Graph Paper" at www.tata-tatao.to/knit/matrix/e-index.html.