We print a few thousand customer designs a month through the Design Lab, and when one disappoints, it's almost never the press's fault — it's one of four patterns that were invisible on a backlit screen and obvious on cotton. Here they are, so yours isn't one of them.
Pattern one: hairline detail. A one-pixel line at 1200 dpi on your monitor is thinner than a single thread of a tee. On paper it might hold; on fabric it stitches itself into noise. Our rule of thumb is that any stroke you'd squint at when the design is the size of a postage stamp needs to be doubled before it goes near a garment.
Pattern two: screen-glow color. Monitors emit light; ink reflects it. Neon gradients and saturated RGB blues physically cannot exist in pigment, which is why the Design Lab shows a gamut warning instead of quietly shifting your colors and letting the box surprise you. If the preview shows the warning, trust it — desaturating 10% yourself beats the press desaturating 25% for you.
Pattern three: low-resolution uploads stretched to poster size. A 1080-pixel Instagram export printed at 24×36 gives every edge a soft halo. We flag anything under 150 effective dpi at the size you've chosen, and the fix is usually free: most creators have the original file sitting one folder away from the export they uploaded.
Pattern four: forgetting the substrate is part of the design. White ink on a kraft tote reads completely differently than black ink on a white tee — the material is a color in your palette whether you chose it or not. The designs that look intentional, the ones we pin to the shop wall, are the ones that used the shirt, the mug curve, or the paper tooth instead of fighting it.