Sublimation Transparent PNG: How to Remove the White Box

Sublimation only works with a genuinely transparent background. If a white (or off-white) rectangle shows up around your design when pressed, the transparency didn't survive. Here's the fix for each common cause.

Cause 1: You saved a JPG, not a PNG

JPG cannot store transparency — it fills empty areas with white. If you exported JPG anywhere in the chain, that's your white box. Only PNG (or a transparent-capable format) holds transparency. Re-export as PNG.

Cause 2: There's a hidden white background layer

In Canva, Photoshop or Procreate, a white background layer is often still there, just behind the design. Delete or hide it before exporting. In Canva, remove any background color; in Procreate, turn off the "Background color" layer; in Photoshop, delete the white layer so you see the checkerboard.

Cause 3: The design was flattened onto white

If you flattened the image at any point, the transparency baked into a white fill. Go back to the layered version, remove the white, and re-export.

Cause 4: A near-white halo

Sometimes the background is transparent but there's a thin off-white edge from anti-aliasing. On a white shirt it's invisible; on a colored garment it shows. Tighten the cutout or add a subtle matching edge.

How to confirm it's really transparent

Open the PNG over a colored background (drop it on a dark canvas). If you see the color through the empty areas, transparency is intact. If you see white, it isn't.

Getting the size right too

Once your PNG is truly transparent, it still needs to be the correct press size at 300 DPI. Use the free Sublimation Size Guide for exact design dimensions and placement on tees, tumblers and mugs, so the transparent design also presses at the right scale.