Go West, Young Standards Seekers
As members of the publication community, we feel it's important to revisit the reasons why we should all be interested in PDF/X-1, so let's take a closer look at the file format. The PDF/X standard represents a series of file formats designed for a variety of applications. PDF/X-1 is aimed at digital ad delivery, hence the support of organizations like the DDAP and the Newspaper Associ-ation of America (NAA).
Adobe's PDF is extremely flexible, which in the case of advertising, causes some concern. So, PDF/X-1's purpose was to limit the format's flexibility without limiting its usefulness and richness. Here's how PDF/X-1 differs from PDF:
Fonts: Fonts in a PDF document, for example, may be embedded, while in a PDF/X-1 file, they must be embedded. High-Res/Low-Res: With a PDF, you can use OPI (Open Prepress Interface). With PDF/X-1, OPI is out of the question, for all high-resolution data must be embedded.
Color: With standard PDF documents, the creator can chose from a variety of color spaces, but PDF/X-1 only allows for CMYK and spot-color designations.
Embedded files: PDF provides no allowance for embedding legacy file formats within the document, but PDF/X-1 does.
File formats: With PDF, there's virtually no limit to the number of file formats that can be included in the document. PDF/X-1, however, limits the files to: TIFF/IT-P1, DCS five files (also called DCS 1) containing only CMYK raster data, DCS 2.0 containing only CMYK raster data and EPS, also with only CMYK raster data.
Trapping: A recipient of a PDF 1.2 file can't tell whether the file has been trapped. PDF/X-1 (and PDF 1.3 or higher) offers a "flag" that alerts operators about trapping.
Boxes: With PDF, there is an allowance for media, art, trim and bleed boxes, but they are optional. With PDF/X-1, art and media boxes are mandatory.