What DPI do you need? Nothing — it's handled

Nothing. You don't need a DPI.

That's the whole answer and it belongs at the top rather than at the bottom of a long article. File resolution, sizing for the press, and enlargement are pipeline work and they happen on this side.

What follows is the mechanism, because the arithmetic is genuinely interesting and it explains several things people worry about for the wrong reasons.

What does DPI actually mean here?

Dots per inch — how many marks land in one inch of the printed result. It's a relationship between a file's pixel count and the physical size it's printed at, not a property of the file.

The arithmetic: an image 1024 pixels wide, printed 12 inches across, gives 1024 ÷ 12 ≈ 85 DPI. The traditional print standard is 300 DPI, with 150 usually considered the floor for something you'd look at closely.

By that maths, a great many AI-generated images look alarmingly short. That's the calculation behind most of the anxiety on this subject, and it's also where the reasoning usually stops.

So is 85 DPI a problem?

Much less than the number suggests, for two reasons.

Enlargement isn't nothing. Getting from a generated image to a press-ready file is a solved step. It happens here, and it's not something you supply or specify.

The fabric has its own ceiling anyway. Knitted cotton is loops of yarn, and the surface can only hold so much detail regardless of the file — the weave is a grid with a resolution. A 300 DPI file and a well-enlarged 150 DPI file frequently land on cloth looking identical, because the limiting factor stopped being the file.

Paper is a much finer surface than jersey. Most DPI advice was written for paper.

Then what does actually limit print quality?

The character of the image, not its pixel count.

A bold graphic with hard edges and flat colour enlarges beautifully — there's nothing subtle to lose. A soft, atmospheric, low-contrast image at exactly the same resolution goes to mush, because what made it good was fine tonal information that doesn't survive.

Which reframes the question people are asking. It's rarely "too small" and usually "too soft".

Is there anything on my side?

One thing, and it's about where the file came from rather than its size.

A screenshot of an image is a re-photograph of a screen: the pixels that were thrown away are gone permanently, and enlargement will faithfully sharpen the compression artefacts along with everything else. Same for an image saved out of a chat app that recompressed it.

Bring the original file. That's the only file-side thing that matters, and it matters because the missing information genuinely cannot be recovered — unlike resolution, which can.

Why does everyone say 300 DPI, then?

Because it's the standard for commercial paper printing, and it got copied across without being re-examined.

At 300 DPI a printed page holds detail beyond what the eye resolves at reading distance. That's a sensible target for a magazine. A t-shirt is looked at from two metres, on a textured surface, and the same target is well past the point of diminishing returns.

It's a good example of received wisdom outliving its context — the number is correct for the medium it came from and was never re-derived for this one.

What size is the print, physically?

The statement zone runs about 38% of the garment's width, which works out around 20 cm on the smallest size and 26 cm on the largest — roughly the width of a sheet of paper.

So the honest version of the arithmetic: a 1024-pixel image across roughly 8 inches is closer to 128 DPI than 85, before any enlargement. The scary number people calculate usually assumes a print much larger than the one being made.

How do I get one made?

Describe the idea at JustOG or upload the original file — not a screenshot. 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 number is real. It's just answering a question about paper.