From my mail:

You stress the need to use a size Medium as sampling size but the thing is, I sell more size 8’s (smalls) than any other size, which is why I sample and fit in size 8. I thought I could continue with that and create larger patterns for markers later when production is given the green light.

When I wrote about using a size medium in the Entrepreneur’s Guide, it was from a generic standpoint. The better explanation there would have been to use your median size rather than medium size. In other words, whichever size you sell the most of, is your median size so in your case, of course you should use a size 8 because that is your median size -the “average” size you sell. The issue of stock size is from a utilization standpoint, that is your “medium”. This is not a sizing issue. Whatever the mid point of your size run is, is what you use as your “medium”. This applies to whatever sex or sizing category that applies to your product line.

I’ll be running another sizing question tomorrow. In the meantime, feel free to add your questions via comments.