Why the size bands overlap on purpose

No print here — two tees, one size apart, stacked so the difference at the hem and the shoulder is visible but small.

That gap is the whole subject. It's smaller than people expect, and a good chart already accounts for it.

Why do the recommended size ranges overlap at all?

Because a lot of people genuinely fit two sizes, and a chart that overlaps is saying so rather than hiding it.

Somewhere in the middle of any two adjacent bands there's a stretch of heights and weights that sits inside both at once. That isn't an edge case the chart missed. It's the honest answer for everyone in that stretch.

Is the overlap a flaw?

No — the alternative is worse.

A single dividing line between two sizes draws an arbitrary boundary through a group of people who are, for sizing purposes, equally well served either way. Someone a centimetre on the wrong side of it would be told something false with total confidence. The overlap is the chart declining to do that, and handing the choice back.

So what actually decides it, if not fit?

Silhouette, once you're inside the overlap.

This is the part people miss. In the overlap, the smaller size already fits — going up isn't buying safety margin, it's choosing a looser shape over a closer one. Both are legitimate answers to different questions, and neither is a hedge against getting it wrong.

It matters most on a cut that's already relaxed, where the extra room you'd be reaching for is already in the pattern rather than something a size step has to supply.

What if my height and weight point to different sizes?

Decide which of the two you'd rather get right on this particular shirt.

Height tracks the shoulder line; weight tracks the chest. When they disagree you're choosing between a size whose shoulder sits better and one whose chest does — which is a real preference, and the reason a chart keyed to the body works at all.

What actually changes if I take the larger of the two?

More than one thing, which is the part worth checking before deciding.

A size step doesn't move a single measurement — it moves all of them, each by its own amount, and the ratio is rarely the one you had in mind. Reading the two rows of the chart side by side answers this in ten seconds and settles it properly.

How do I get one made?

Describe the design at JustOG — a garment, and either of the two sizes you're weighing up. Pick a direction, drag the crop frame, see it composited on the real garment, and it's made to order and shipped.

Designs other people have published are in the shop.

At the edge of two bands, the chart isn't unsure. It's telling the truth.