Nice write up and comparison
@Wlemon, thanks. As you say, the IHSH-13-BLU and IHSH-21-BLU are the same material. The colour variation can come from different batches or their age/usage, or both. Also worth noting that they aren’t indigo dyed while the IHSH-250-IND is.
Finally, while they are both chambray, the linen will make a difference to the hand, as will the fact that the 250 fabric is only half the weight per square yard if the 13 and 21. The latter come in at 10oz.
Edit: they also all look great on you.