I should know by now that laziness doesn’t pay. It’s inefficient in the long run. So I should probably have been able to guess that attempting to construct a border in my head was going to be an exercise in futility.
After an evening’s frustration scribbling cryptic numbers in a notebook and trying to make them fit the number of stitches I had for a border and factoring in the increases as the border grows outwards I realised that it would be easier to do it the proper way. So I went and bought some graph paper and discovered again that sometimes the long way round is the shortest route.
My only gripe is that when I get a bit wrong and erase the pencil marks from the graph paper it generally takes the graph paper with it, so there’s an element of squinting at the paper trying to work out where the little squares used to be. So now I have the usual mob-cap effect which is the downside of knitting a shawl borders-outwards!