On January, 11th I have conducted a webinar for the Ghent Workgroup (GWG) on the Ghent PDF Output Suite 5.0 for which I am the project leader in my role as co-chair of the Process Control subcommittee of the Ghent Workgroup.
In the upcoming weeks the Ghent (PDF) Workgroup (GWG) is organizing a series of free webinas. These webinars are hold by well known PDF experts from Europe and the US. Recordings of past webinars are also available.
I will conduct a webinar about the Ghent PDF Output Suite on January 11th, 2018.
Martin Bailey, CTO of Global Graphics (Harlequin-RIPs), talks in his blog about tests to avoid the orange peel effekt for inkjet presses using special screening methodes.
When inkjet presses print on non-absorbent, poorly wettable media such as flexible plastics or metal, prints are characterized by a mottle effect that looks a bit like orange peel. This effect seems to be triggered by ink shrinkage during cure. This can be corrected with a halftone with specially designed characteristics.
In order to avoid these artifacts Global Graphics will soon introduce a new screen technology.
It’s interesting that the topic of screening becomes important again for the new printing technologies…
The question of the last survey was how many of your PDF files are checked by a Prelight tool.
The result of the last survey on how many PDF files are checked by a preflight tool is surprisingly very positiv. The majority of the PDF files of the readers of PDF-AKTUELL run through a preflight check. But there are still almost 20% of the users were less than a quarter of the PDFs are checked:
In preparation of my new seminar PDF Color Management I have tested the image compression before and after color conversion in the most popular PDF tools.
In highend PDFs destinated for quality printing the images are usually compressed using JPEG maximum quality. Before color conversion the images must be decompressed and afterwards compressed again. Acrobat always uses JPEG medium quality for this recompression. The consequence is that there is an (unexpected) loss of quality of the color converted images (see table).
ECI has released the ICC color profile eciCMYK.icc. It’s based on the printing condition FOGRA53 defined by Fogra. The goal is a large gamut exchange space which covers all printing technologies (offset, gravure, digital). The eciCMYK profile can be download for free.
Since the gamut of eciCMYK is larger than any real printing gamut and the profile allows a high total ink coverage (TAC), this profile is not suitable for printing.
After nine years of (hard) work the ISO has published PDF 2.0 as ISO standard 32000-2:2017. This is the first PDF specification which was completely developed by more than 30 PDF experts from all over the world in an ISO working group. ISO 32000-1:2008 was basically a takeover of PDF 1.7 from Adobe. PDF 2.0 is more an evolution than a revolution. An important goal was compatibility to older PDF versions.
Seven chapters of the specification (971 pages in total) have been completely rewritten (e.g. transparency, tagged PDF). The goal was not to introduce new features but to eliminate ambiguities and errors of old specifications.
- Setting to activate black-point compensation (BPC) for each object. This allows to define predictable color conversions.
- Output Intent per page (optional). E.g. Coated for the cover pages and Uncoated for the body pages of the same PDF.
- Use of spectral data for spot colors (using CxF/X-4).
- Definition of the printing order (e.g. for sheetfed offset).
- Enhanced halftone features (origin, halftone dot shape).
The Ghent Workgroup (GWG) has published an interesting poster:
On the front page the GWG is presented. On the back nine reasons to preflight are listed (compiled by belgian VIGC). Each topic is illustrated with an eample.
This page can be used to check how certain PDF definitions are displayed in different viewers (Acrobat/Reader, Apple Preview, etc.) and output devices (printer, proofer, imagesetter).
In addition one should check this PDF with a preflight tool in order to also detect the problems which are not visible. For this the preflight profiles GWG2012 or GWG2015 (part of Acrobat DC Pro, Callas pdfToolbox, Enfocus PitStop Pro) and of course the preflight profiles for Acrobat Pro from PDFX-ready are highly recommended.
For the new Adobe InDesign export settings V2.5 for PDF/X-4 CMYK+RGB from PDFX-ready the technical committee of PDFX-ready has investigated if a change of the compression method from the traditional JPEG to the newer JPEG2000 would be useful.
JPEG2000 uses a completely different compression technology (wavelet transformation) than the old JPEG (discrete cosine transformation). The new technology promises a better quality together with smaller file sizes. JPEG2000 also allows images with more than 8 bits per channel and up to 256 channels. That sounds promising…
We already knew from tests of the Ghent Workgroup that not all PDF viewers (especially on mobile devices) can handle PDFs with JPEG2000. With other PDF viewers (including Acrobat/Reader) displaying JPEG2000 images is much slower than JPEG images.
But after all we wanted to know if we could recommend JPEG2000 compression for prepress data. That’s why we decided to perform a series of practical tests with a calendar with highres images in different color spaces (Device-CMYK, ICC-CMYK, ICC-RGB). Peter Kleinheider has done the output tests with two different RIPs and I did the export tests with Adobe InDesign CC2017.
When comparing the test results we noticed some unexpected surprises!
Software developer CSci from Hamburg has released ChkBarcode. This software allows checking of barcodes in PDF files for printing.
ChkBarcode checks quickly and securely all barcodes directly in the ready-to-print PDFs. The verification software ChkBarcode finds 1D and 2D barcodes, determines the type, reads the contents and measures the quite zone, checks the dimensions, measures the barcode elements and determines the bar width reduction (BWR). With ChkBarcode, you can create a QS report and use the results to control your workflow.
There is a problem with PitStop Inspector in Acrobat DC 2017. After starting Acrobat it is impossible to select an object with the PitStop Inspector tool.
This is also true for older versions of Enfocus PitStop. The reason for the problem seam to be a change in Acrobat DC 2017. Enfocus is working with Adobe to find a solution.
The recommended workaround is to open the window Adobe Acrobat DC > About Third-Party Plug-Ins > About Enfocus PitStop Pro… and close it. Afterwards objects can be selected as usual … until the next start of Acrobat DC 2017. Then you have to open the About Enfocus window again!
UPDATE: the problem has been fixed by Adobe in the November 2017 Update of Acrobat.
After the confusing version jump of the Acrobat update in April Adobe now has also released Version 2017 of the perpetual license of Acrobat (classic track). Please note that the perpetual version has lost the amendment DC and now is only called Acrobat 2017.
The users of the perpetual version eventually can also benefit of new features of the subscription version:
- Easily compare files
- Tabbed interface
- Bulleted lists
- Scan to PDF
- Digitale ID’s
- Improved tools search
- Shared reviews on Mac
- Dark user interface
- Enhanced commenting
- Draw using DirectInk (Windows 10)
- Preview files on Home page
On the Acrobat 2017 FAQ page one can find a somewhat longer list of new features. But also there several features of the subscription version are missing. E.g. the enhancements of preflight and accessibility. However I don’t know if these features just have not found their way into these lists or if the perpetual version really has fewer features that the subscription version…
Acrobat 2017 is a paid update for users of Acrobat XI and Acrobat DC (Classic).
- The history of PDF/X
- PDF/X: The key facts
- Technical side and requirements of PDF/X
- Users and industry segments
- Tools and usage
- PDF/X and the other PDF standards
I have contributed a chapter on PDF/X-Plus (about the Ghent Workgroup and PDFX-ready).