What resolution does a T-shirt print file need?

An image file has a fixed number of pixels. DPI, dots per inch, only says how densely those pixels will be laid onto the fabric, and that is decided by how large you print the image, not by a number saved in the file. Adobe's explainer separates the two terms: pixels per inch describes the digital image, dots per inch describes the ink on the print, and the density is simply pixels divided by inches.

So a file tagged 72 DPI is not low resolution, and a file tagged 300 DPI is not sharp. The tag is a note for software. Midjourney's documentation makes the same point about its downloads: they open in Photoshop at 72 DPI, and you can change the tag to 300 with resampling switched off without changing a single pixel. Printful's help center puts it in one line for printers: resolution is your pixel count, DPI is ink dots per inch, and a high pixel count still prints badly if it is stretched over too large an area.

The question to ask of any image is therefore: how many pixels wide is it, and how many inches wide will it be on the shirt? Divide the first by the second and you have the only resolution figure that matters.

Printful, which prints Inkdrop's orders, asks for at least 150 pixels per inch at the actual print size for apparel, and says 300 is fine and may look a little sharper on small detail. Its own worked example is the 12 by 16 inch front of a T-shirt: at 300 pixels per inch that is 3,600 by 4,800 pixels; at the 150 floor it is 1,800 by 2,400.

Most people do not print the whole front. Printful's placement guide puts a typical center-chest design at 6 to 10 inches wide, so an image 1,500 pixels wide covers a 10 inch print at 150 pixels per inch, and a 2,000 pixel image covers it at 200. A left-chest mark of 3 to 4 inches needs only 600 pixels at the floor. The bigger you print, the more pixels you spend per inch.

In Inkdrop you do not have to do the arithmetic. When you pick a product in Create, the Recommended artwork line shows the print area of that exact garment in inches and the matching pixel count at 150 pixels per inch. Adult T-shirts in our catalog print on a 12 by 16 inch area front and back; hoodies differ by style, with the Gildan Heavy Blend hoodie at a 14 inch square on the front; the Eco Tote prints on about a 10 inch square. Our design size guide covers how large to make the print; this guide is about whether the file can carry it.

Enlarging an image spreads the same pixels over more inches. Printful's example is a 5 by 5 inch image at 100 pixels per inch: stretch it to 10 by 10 inches and it is now 50 pixels per inch, and blurry. Its print-file guide works through a worse case, a 335 by 410 pixel image dropped onto the 12 by 16 inch area, which comes out at about 60 pixels per inch. The help center's advice is blunt: do not enlarge a small, low-resolution image.

AI upscalers blur the line here. Midjourney's Creative upscaler, for instance, is described as adding or altering detail, which can look good and can also change the drawing. Tools like that are a way to get more pixels when you have no better source, but they are inventing what they add, so look closely at faces, lettering and anything that must stay exactly as it was.

The reliable fix is to go back to the source. Re-export from the design tool at full size, re-download from the AI tool instead of saving a thumbnail or a screenshot, or photograph the original artwork again closer and in better light. How print on demand works explains why no printer can put back detail the file never had.

PNG is lossless and carries transparency; JPEG is lossy and has no transparency, which is why MDN's format guide recommends PNG for line art, diagrams and anything that must be reproduced exactly, and notes that JPEG compression leaves blurring and colored fringes around sharp edges and text. On a shirt those fringes print.

Printful asks for PNG when the design should sit on the fabric without a box behind it, because a JPEG arrives with a white rectangle. A photograph with a solid rectangular background is fine as a JPEG. Lettering, line art, logos and any cut-out artwork belong in a PNG. Inkdrop accepts JPEG and PNG uploads and nothing else; vector files such as SVG or PDF are not accepted, so export them to PNG at the size you need before you upload.

Watch for one Photoshop habit: the Save for Web dialog often writes a shrunken 72 pixel per inch copy, which Printful calls out as a common cause of grainy prints. Export at the original pixel size and check the dimensions of the file you actually uploaded. Our transparent or solid background guide covers what the background should do once the format is right.

Printful prints from sRGB files and asks you not to convert to CMYK yourself, because the conversion throws away color information and its printers use inks beyond the four CMYK colors. Colors outside what the ink can reproduce are mapped to the nearest printable color, which is why saturated neons and electric blues come out a step duller than on your screen. Threadless's direct-to-garment guide suggests pushing saturation up ten to twenty points on bright colors to compensate.

On dark shirts every color sits on a white underbase printed first, and on black shirts a black design prints as a slightly gray rectangle rather than disappearing into the fabric. If part of your artwork is meant to be the shirt showing through, make it transparent rather than black.

Resolution is not the only thing that softens on cotton. Printful's file guide warns that small text and thin lines can lose sharpness and fade into the fabric texture, without giving a number. Threadless does: on its 14 by 16 inch, 300 pixel per inch template it asks for lines no thinner than 2 points and text no smaller than a quarter of an inch, about 18 points, with a bolder face for anything small.

Semi-transparent pixels are the other trap. Direct-to-garment ink cannot be thinned, so a soft shadow, a glow or a feathered edge is printed as scattered dots, and on a dark shirt the white underbase shows between them as speckles. Printful's advice is to keep edges hard and simulate fades with a halftone pattern of solid dots. The design size guide has a paper mockup test that catches lettering that is too small before you order.

When your artwork is on the product in Create, switch to Design view and zoom into the parts that have to be right: lettering, eyes, the edge of a cut-out, any thin line. Then switch to Product view and look at the whole garment at the size you chose. The preview is a mockup, so a file that already looks soft there will not sharpen on fabric; Printful's own guidance is that sharp on screen is not a guarantee of crisp on cotton, and soft on screen is a guarantee of soft on cotton.

If the file is short of pixels, this is the moment to fix the source rather than the size: a smaller print at the same pixel count raises the pixels per inch, and the order checklist walks through the last look before checkout. As of November 2026, T-shirts start at $15.03 and the exact price shows before you order.