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.
Datalogics, distributor of Adobe software libraries for developers, has publisher a knowledge base article on a new error in version 3.0 of the Adobe PDF Print Engine (APPE) called NON-FATAL PDF Exception: Cannot extract the embedded font. This error message generated by the Adobe Common Renderer is caused by bad font data. The article describes settings which can prevent this error message (but adds the risk of wrong display of fonts).
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…
In the morning of Octobre 26th, 2016 we have launched the PDFX-ready Online Tools. which I had developed for PDFX-ready. Right at the beginning we offered three tools:
- PDF Preflight (with the well known PDFX-ready preflight profiles)
- Color Preflight (Analysis of the undefined color spaces in a PDF)
- ISO<–>PSO Converter (for color transformation between the old and new offset standards)
The experience we made in the past year is pretty good. The Enfocus Switch server with the applications Callas pdfToolbox and ColorLogic ProfileTagger is running very stable. But of course there were a few problems.
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).
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!
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.
PDFX-ready has update their preflight profiles for Acrobat Pro. The latest versions feature the following changes:
- V2.5 (for PDF/X-4):
- Removed check for single-color hairlines (< 0.125 pt) since these lines are no longer problematic in modern CTP and Digital workflows.
- Check of multi-color objects (text < 8 pt; lines < 0.25 pt) also for Digital Printing.
- More details in explanation for spot color check.
- Compatibility with PDF/X-4 created by QuarkXPress 2016/2017.
- V1.5 (for PDF/X-1a and PDF/X-3):
- New checks for recognition of black texts and vektors which most probably were re-separated (was alredy in V2.4).
- More details in explanation for spot color check.
- Removal of check “Annotation of this type not allowed (GWG)” (alignment with V2.x).
The biggest problem in PDF workflows for print production is certainly the topic of color. Often there are surprises after printing because the printed colors do not meet the expectations.
PDF/X files have a mandatory output intent but often the color spaces of the objects in PDF/X documents do not match the output intent.
This can be checked very easy with the Color Preflight of the PDFX-ready Online Tools.
Since this happens frequently and the reason is often lack of know how I have decide to create a seminar entitled PDF Color Management (for now only in german). This will be offered at the usual places in Germany, Austria and Switzerland. The first seminar will take place in Olten on 31.8.17.
On the web site of the Ghent Workgroup one can find the settings used for the successfull output of the Ghent PDF Output Suite 5.0 (also for some other vendors).
Agfa offers in Apogee Prepress 10 a choice of two different preflight processes. Apogee Preflight is a solution developed by Agfa while Preflight is based on Enfocus PitStop. For both there are now preflight profiles available which are compliant with the lastest GWG2015 specifications of the Ghent Workgroup.
In a short instruction the use of the GWG2015 profiles with both preflight processors in Apogee 10 is described.
Callas software has created a comprehensive online help for pdfToolbox, pdfChip and pdfaPilot. One can find an overview of the new features of the latest versions with step-by-step instructions and a lot of screenshots. These pages shall be extended in the future.
The latest version 1.7.080 of the InDesign plug-in MadeToTag from Axaio, known for the features for the definition and export of tagged PDF (PDF/UA), now also comes with a feature for better export of form field properties out of InDesign.
Since longtime the Adobe layout application offers the possibility to define form fields directly in the layout. During PDF export they are converted to PDF form fields. Unfortunately the possibilities for the definition of the form field properties in InDesign are very limited, compared to what can be done in Acrobat. That’s why a lot of users still prefer defining their form fields in Acrobat. Which has the disadvantage that one has to update the form fields after each change of the form layout.