Between Ravelry and just the internet in general, knitting patterns get swopped between countries and continents, and — guess what? — not everybody uses the same system of measurements either of yarn thickness or of knitting needle diameters. Here are two charts, Ravelry’s Standard Yarn Weighs, and a needle size and conversion chart I found on the internet so long ago I’ve forgotten now where I found it. I’ve put them both on the same page so you can print them out on a single sheet and keep them handy. Here is both PDF format and chart format. To download the PDF, you’ll need to click on the link to go to a separate page, then click on the link again to display the PDF file because I don’t know how to get it to just display the PDF file!