Best DPI and Upscaling Settings for Midjourney and AI T-Shirt Prints

An AI image can look perfect on a phone and print like a photocopy of a photocopy. The picture is fine. It is small: most image models, Midjourney included, hand back about a megapixel, around 1024 × 1024 pixels. Spread over the front of a shirt, every one of those pixels is stretched to the size of a grain of rice.

This guide gives the numbers: how many pixels a shirt print needs, which settings to pick when you make the image, and how far to upscale it. The free print size calculator checks any file in seconds.

The numbers a shirt print needs

Print quality is measured in DPI: how many of the image’s pixels land on each inch of fabric. The sum is pixels divided by inches.

• 300 DPI is the standard for anything seen up close. On a 15 × 18 inch shirt front it means 4500 × 5400 pixels.
• 200 DPI is plenty for most shirts and hoodies. Fabric softens fine detail, so the eye cannot tell it from 300 at a normal distance.
• 150 DPI is the least most print-on-demand suppliers accept. It holds up from a step back, but soft edges and blocky gradients start to show.

A 1024 pixel image is a sticker. For a full shirt front it needs to be about four times bigger on each side.

Settings to choose when you make the image

1. 1
   Match the shape of the print area

   A shirt front is taller than it is wide. In Midjourney, add --ar 5:6 (the shape of 15 × 18 inches) or --ar 4:5. A square image on a shirt leaves part of the print area empty, which is fine for a chest logo but wastes pixels on a full front.
2. 2
   Ask for a plain background

   A flat white or black background is much easier to remove cleanly than a busy scene, and the cut-out is what gets printed.
3. 3
   Use the generator’s own upscale first

   Midjourney’s Upscale buttons double the image to around 2048 pixels. Use Subtle when you like the picture as it is; Creative may change small details.
4. 4
   Keep fine detail in proportion

   Hairline strokes and tiny text are the first things a print loses. Ask for bold shapes, thick outlines and a clear silhouette.

How far to upscale

After the generator’s own upscale, a 2048 pixel image is still only 137 DPI on a full shirt front. One more 2× step takes it to 4096 pixels and 273 DPI, which is as sharp as fabric shows. Starting from 1024, a single 4× step does the same.

The image upscaler does 2× or 4× and keeps a transparent background. It has three ways of working:

• Faithful keeps the picture as it is, only sharper. The safe choice for logos, lettering and flat cartoon art.
• Restore also cleans up blur and noise, which helps an image that was already soft.
• Enhance invents fine detail. It suits painterly and photographic pictures, but faces and small objects may change, so look closely before you print.

Check it before you order

1. 1
   Check the size

   Put the file into the print size calculator. It shows how large it prints sharp and how it does on a shirt, a hoodie, a mug and a poster.
2. 2
   Check the background

   A shirt print needs a transparent PNG. The transparent PNG checker finds the faint leftovers that print as a haze on dark fabric.
3. 3
   Check the colors

   Neon and glowing colors print duller than they look. The print color checker marks the ones ink cannot reach.

In the SlapMake studio, the order screen does the size check for you: when a design would be stretched too far on the T-shirt or hoodie you picked, it says so and offers to sharpen it first.

Questions people ask