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Pressline

Files, DPI, color, transparency

  • Format: PNG for anything with transparency (DTG, DTF, embroidery placements, UV); PNG or JPEG for all-over and sublimation where the Spec forbids alpha. formats in the Spec lists what a placement accepts.
  • Size: the placement’s print area in inches × its DPI, rounded to pixels: a 12×16 in DTG front at 150 dpi is 1800×2400 px. The Spec states the exact pixels; Pressline rejects anything else.
  • DPI: stamped in the PNG’s pHYs; providers read pixels first, but the stamp keeps preview tools honest.
  • Color: sRGB, 8 bits per channel, declared with sRGB + gAMA. Embed the sRGB profile if your exporter writes one — Printful asks for it; never embed a CMYK or grayscale profile. Expect DTG prints darker and less saturated than a screen; avoid relying on pure neon.
  • Transparency: alpha: "allowed" — transparent pixels print nothing (garment shows through); forbidden — the file must be opaque (flatten onto the product color or white); required — reserved in the Spec for placements that need transparency; Pressline’s Printful catalog derivation today produces only allowed (DTG, DTF, embroidery, UV) and forbidden.
  • Bleed: none for DTG/DTF placements. For all-over and sublimation products check Printful’s placement documentation for whether the print area includes bleed; Pressline passes the provider’s dimensions through unchanged.
  • Color type: Pressline reads the PNG header, the first 64 KiB: color type 4/6 or a tRNS chunk means alpha, and reaching IDAT without one means none. If the chunk table runs past 64 KiB before IDAT, Pressline cannot tell either way and a placement whose Spec is forbidden or required rejects the file. Keep ancillary chunks (iCCP, eXIf, text) small enough that IDAT starts inside that window.
  • What Pressline verifies: exact size; 8-bit; non-interlaced; not palette-indexed; a declared color space that is not CMYK or grayscale; alpha per the Spec; a file under 200 MB. Everything else on this page is advice Pressline records as a Deviation when the file departs from it, and shows the Operator; it does not block a sale.