A copy proves the idea was worth stealing
The shirt on the right is recognisably the same design and visibly worse. Both halves matter, and the fact of a copy is information you didn't have last week.

Same crescent, same anchor, same idea. The one on the right is thicker where the original is fine, crooked where the original is square, spaced by eye rather than by measurement.
Anyone who cares about this design can tell which one came first. That's most of the story.
What actually happens when a design gets copied?
It costs some sales, and it costs less reputation than it feels like it should.
The instinct is to treat a copy as a direct hit — every sale it makes is a sale you didn't. Some of that's true. What's less obvious is that the audience who actually cares about a design like this one notices the thicker lines and the lopsided anchor immediately, because they were paying attention to the original for a reason. A worse copy doesn't fool the people who mattered.
So it doesn't matter at all?
It matters, just not in the way the first reaction assumes.
The financial cost is real and worth being honest about — some buyers won't look closely enough to tell, or won't care. But the reputational fear usually outruns the actual damage, because a recognisable original next to a rougher copy reads, to anyone who looks at both, as exactly what it is.
What's actually worth learning from it?
That somebody thought the idea was worth stealing.
That's new information. A design nobody bothers copying is a design nobody thought was working. The copy is confirmation, arriving in an unwelcome form, that the crescent-and-anchor idea landed with somebody enough that reproducing it seemed worth the effort. Most designs never get that signal at all.
Is there anything worth doing about it?
Keep your originals and your dates.
The working files, the drafts, the date the design was first published — hold onto them, because they're the plain record of which one came first if it's ever in question. That's a habit, not a project, and it costs nothing to maintain.
Where it stops being an article's job
Beyond keeping records, this becomes a specific legal question — what a given copy actually infringes and what, if anything, to do about it — and that's a question with a real distinction behind it, worth understanding on its own terms rather than one this piece can walk through. Past keeping your own house in order, it's a question for somebody qualified, not a checklist.
Does a copy mean I should have hidden the design better?
No — a design nobody can see also can't be worn, bought, or recognised.
Every visible design is copyable in principle, and treating that as a reason to obscure your own work trades a real, ongoing benefit — being seen and bought — for protection against something that may never happen. The shirts that never get copied are mostly the ones nobody noticed.
Should I redesign it or move on?
That's a judgement about the design, not about the copy.
A copy existing doesn't make the original wrong, and it doesn't obligate a response beyond the one above. Most people who find out their design was copied keep selling the original exactly as it was and put the energy into the next one instead.
Does this change how I should design next time?
Not the drawing — the specificity is still the point.
The features that make a design sell — a real reference, a specific audience, a joke that lands for one group — are the same features that make a copy conspicuous, because a crude version of something specific is more obviously crude than a crude version of something generic. Specificity didn't cause the copy. It's what makes the copy visible for what it is.
How do I get one made?
Describe the idea at JustOG — the next one, drawn your own way. 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.
The anchor on the left still hangs straight.