Printing PDF with transparent background and white text

Photoshop definitely supports transparency in PDF, I’ve seen it many times.

After some experimentation, I figured out how to ensure that it’s preserved. But…

You need to go back to your printing company and ask them for their exact requirements for submitting PDF files for this specific job type. It’s because there are options you can change to make it work, but the options interact with PDF standards, and there is additional uncertainty about your white text. You could simply push some buttons and get something that achieves transparency on your end, but if there is just one setting that happens to conflict with or be unsupported by the printing company’s equipment and workflow, that may cause unexpected output or delays/extra costs.

More details about that:

One factor is whether Preserve Photoshop Editing Capabilities is selected in the Save Adobe PDF settings dialog box in Photoshop. If it’s selected, my testing shows the PDF does get a transparent background. So, a quick answer is to turn that on. It is also turned on by choosing the Adobe PDF Preset named High Quality Print.

Here’s the catch: To make sure jobs come out as expected on their equipment’s specific setup, some printing companies require exporting to a specific PDF standard or Adobe PDF Preset. But some PDF standards and Adobe PDF Presets do not allow Preserve Photoshop Editing Capabilities to be enabled, and so if you choose one of those standards, that option becomes disabled and unselectable, meaning no transparency. To avoid a potential settings conflict, you need to ask the printer what Photoshop PDF settings they recommend that will preserve transparency and is fully compatible with their workflow. 

There is, as they say, one more thing: You said the job is white letters on a clear background, and they want CMYK. If that’s a normal print job on a CMYK press, how is the Photoshop document set up for the white text? If was set up by creating a text layer and assigning CMYK (0,0,0,0) to it, then it will print nothing, because 0,0,0,0 does not print white, it prints no ink…you see the color of what it’s printed on (paper, T-shirt, mug…). There is no combination of CMYK inks that will give you white.

To print white, did the printer say anything about spot colors? Because if the print job is supposed to be white ink on something, then the press will need to lay down actual opaque white ink. Because white ink is not part of the CMYK ink set, the job requires a spot color ink/channel to print white ink (or remapping one CMYK ink to white ink, if that is how the printer does it on their press).

Because there are multiple possible answers and not all of them may be compatible with the printing company’s setup, you have to ask the printer:

• To print white ink, what Photoshop color mode and channel setup do they recommend? 
• What is their recommended combination of Save Adobe PDF settings for preserving white ink and transparency in PDF? 

Photoshop may not support transparency in PDF. You should probably output with InDesign or Distiller, or send artwork in TIFF or PSD format.