TL;DR
Make "A"-measurement of merch T-shirt to be a chest-circumference, not a half chest.What ?
In the merch-store https://www.factorio.com/store there is sizes chart for official T-shirt and it's main measurement relates to half-chest which is not very useful. I suggest to change it to chest circumference to make it easy to choose.Why ?
In all other online clothes shops sizing charts always refer to circumference sizes of one's body since you just can take measuring tape, wrap it around yourself and that's it. It's not obvious how to figure out half-chest size out of your natural body measurements so the only way to choose t-shirt is to measure some other t-shirt. So first you should have one which suits you properly.I just ordered the T-shirt and was confused in with this case so I thought to bring you this idea. Anyway, I'm looking forward to more factorio merch, since I have 1800+ hours playtime in Steam in it and I definitely love Wube guys working hard on it and I want to support you more in some way, just let me know how