Pixelation

Zoom in on a pixelated print and you'll see individual squares of flat color where a smooth curve or diagonal line used to be — the software has run out of real pixel data and started showing you the pixels themselves instead of the shape they were approximating. It shows up hardest on curved letterforms, circular logos, and diagonal lines, since a grid of squares can only approximate a curve so well before the steps become visible to the eye.

We see it most on social-media profile pictures and phone screenshots — a 400 x 400 pixel Instagram avatar someone wants printed 10 inches across a hoodie back is going to show every square edge on the fabric, not just on a proof. It's an easy one to catch before press time: zoom a file to 100% of its intended print size on screen, and if it looks pixelated there, it'll look pixelated on the shirt.

The only real fixes are sourcing a bigger original file or redrawing the art as vector paths, which have no pixel grid to run out of. Software-based upscaling and "AI enhance" filters can smooth the blockiness cosmetically but don't recover detail that was never captured, so they help a little on photos and do almost nothing for a logo with hard edges and flat color.

Buyers sometimes confuse pixelation with the halftone dot pattern used to print photographic tone through a screen — both look like visible dots up close, but a halftone is an intentional, controlled pattern built to reproduce shading, while pixelation is an accident of stretching a file too far. One is how the printer built the image; the other is how the file broke.