Adobe Acrobat offers a series of presets that a user can choose when creating a PDF. These presets are designed to produce the best results for the intended purpose of a PDF, be it printed on a desktop printer, viewed electronically or sent to a commercial printer. Each preset balances the quality of the file output with how it's going to be ultimately viewed. You can select these presets when exporting a file as a PDF out of document design programs.
Using the setting "High Quality Print" when creating a PDF optimizes the document for quality output on desktop printers and proofing devices. This setting downsamples grayscale and color images to 300 pixels per inch for any images set at a higher resolution. For monochrome images, the setting downsamples to 1200 PPI. This setting does not change RGB color images to CMYK. It flattens transparency in artwork to reduce the file size and embeds subsets of all fonts used. This setting is suitable for files submitted to quick-print shops.
The "Press Quality" preset creates files for high-quality commercial presses. These outputs can be used for digital printing or for creating color separations to send to an imagesetter or platesetter. This setting downsamples images to the same resolution as the high-quality print setting, but includes all information in the file needed by a commercial printer to produce an accurate print. It converts colors to CMYK and preserves transparency, and like the high-quality print setting, it embeds subsets of all fonts. This setting produces the highest quality of file reproduction and results in a large file size. However, you can't assume this is the setting a commercial printer wants for submitted PDFs. Printers often require a more specific preset.
Other Commercial Press Presets
A commercial printer may specify PDFs be submitted as PDF/X-1a or a PDF/X-4 compliant files, which give specific information on how the document is to be printed. Both of these settings set color to appear as CMYK or as spot color, where the color is mixed in a specialty ink and placed on one press plate rather than placing percentages of cyan, magenta, yellow and black inks on four plates to reproduce the desired color on a page. These settings use International Color Consortium color settings and the same color management so that the colors a designer puts in a design accurately matches the color output on the press.
A printer may provide publication designers a ".joboptions" file with settings customized for his operation. The custom setting may specify image resolutions that are higher or lower than those in the standard presets to create the best image on the press and paper used in the job. Placing the .joboptions file in the "Settings" folder of Acrobat allows you to choose the printer's settings when exporting your document as a PDF for printing. Check with your printer before submitting a completed PDF file.