TAC Issues with Black Tones

[csimpson]

I have a bunch of PDF files that are a CMYK build, comprising of text and image elements. Most of the images are CMYK grayscale builds with a few real colored images interspersed. Given my intention to print this file using an inkjet machine on inexpensive paper, I am encountering significant issues with ink bleed-through. My goal is to minimize ink usage. I've executed a TAC (Total Area Coverage) action in Pitstop Server to reduce ink buildups to no higher than 220%, and that has worked great on actual colored images, the images that visually appear as grayscale images are still causing substantial bleed-through problems at this threshold. Is there an automated method to identify these grayscale images and convert them to solely utilize black ink so that the TAC in the areas would be below 100%, while preserving the color integrity of the remaining images?

[bens]

You could try converting these images to DeviceGray. There is a rule in the PDF spec that DeviceGray should be mapped directly to (only) the K channel under normal circumstances (there are exceptions of course). This is a relatively new rule though, so not everything follows it - but it's worth a try.

PitStop's "Select black and white objects" can help to select the relevant images.

[magnussandstrom]

Given my intention to print this file using an inkjet machine on inexpensive paper, I am encountering significant issues with ink bleed-through.

Hi!

How do you send the files to the printer, are you using a RIP? What are the color management settings?

IMHO it's unusual that the CMYK-values in the PDF is printed "as is" on an inkjet printer. In most cases the file is re-separated in the RIP/DFE or by the printer driver. In that case adjusting TAC in Pitstop wont help you to solve the problem.