EPS.

An older PostScript-based format that can hold vector paths, raster images or both, still listed as an upload type by screen printers and UV RIP vendors. Its limit is transparency. ONYX states that EPS files have no support for transparency, so transparent regions are rasterised, and where a spot colour object such as a white or varnish layer crosses a transparency bounding box, the spot data inside that box is rasterised too and the specialty ink will not print there. The same guide recommends PDF 1.4 or higher to keep the transparency and the spot objects. On EPS, ONYX's RIP also needs its overprint option switched on before overprinted objects print as drawn. A drop shadow or a soft glow saved to EPS therefore looks right on screen and prints with a hard-edged hole in the white. If the shop accepts PDF, send PDF.