I know there are knitting needles size in US, and in metric (mm). But I have seen UK measurements, which are labeled “former Canadian” or “old UK” (I have no idea how old). I have also seen Japanese sizes (middle of this page) which are like 5.1mm or 2.7mm. Additionally, needle manufacturers make needles which aren’t quite to the charts, I have a pair of #9 Brittany Birch which are marked 5.25mm, a size which doesn’t even show up on the huge needle size chart in the new Patternworks catalog. I’m curious, do you ever find yourself needing an old UK or Japanese needle size chart? Or have things settled into US and metric (mm) sizes pretty well?