By now, you may have noticed that it seems like no two sewing pattern sizing charts are the same!
This is just a natural result of the passage of time. Over the years independent companies, designers, and regions have made their own systems and regulations for measuring and marketing sewing patterns.
As time has gone on, body measurements have become larger and the size numbers smaller. This is simply the known marketing effect of vanity and people feeling happy to see they fit a smaller size.
As with much of the fashion world, it’s all illusion and delusion.