GWG Specifications and PDFX-ready.ch

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1 GWG Specifications and PDFX-ready.ch Peter Kleinheider PDFX-ready - technical working group Co-Chair of GWG Specifications Subcommittee inpetto premedia consulting, owner

2 What is PDFX-ready Swiss Initiative to make PDF/X successful Work is based on GWG specifications adapted to local needs (mainly for Switzerland, Germany, Austria) offers certification for creation and output provides localised education material and deliverables the PDF/X process PDF/X-1a Workflow Image and artwork Layout PDF/X-1a Output /X Export to PDF/ X-1a (PDF 1.3) GWG 1v4 Check PDFX-ready V1.2 Trapping Export to PDF (via PS) Impose Output Important: all CMYK elements should be prepared for the same printing condition

3 PDF/X-1a creation Image and artwork Layout PDF/X-1a /X Export GWG 1v4 Check PDFX-ready V1.2 Usage of GWG 1v4 mature Specification based on PDF/X-1a, a well recognised and accepted standard (since 2001) all major tools are PDF/X-1a savvy Creation Modification Proof Output So why move to X-4? Live Live Transparency Transparency Live Tran!arency Live Transparency

4 Transparency -the major force to move to PDF/X-4 live transparency is supported since PDF 1.4 classical usage Drop-shadows W e r n o c h n a c h S o m m e r - L e k t ü r e s u c h t : H i e r i s t s i e! Brigitte... gehört zum besten elegischen Ton der Ge genwart. FAZ Eine ungeheuer fesselnde und sinnliche Erzählung von besonderer sprachlicher Schönheit. Eine echte Entdeckung. Amelie Fried in der ZDF- Sendung Die Vorleser So eindrucksvoll ist das Ende der Kindheit lange nicht mehr beschrieben worden. Spiegel Online 224 Seiten, gebunden, mit Schutzumschlag und Lesebändchen 19,90 E [D], ISBN , classical usage clipping

5 extensive use of transparency why keep transparency in PDF? ability to search is preserved higher quality transparency effects are directly rendered to high-res raster image no object clipping no unnecessary trapping where not needed ability to edit is preserved no unnecessary object conversion (Text-2-Outline) keep spot colours definitions till the very end better repurposing faster export smaller files native PDF/X-4 Workflow Image and artwork Layout PDF/X-4 Output /X Export GWG2012 Check PDFX-ready V2 Trapping Export to PDF (via PS and pdfmark) and Acrobat to convert to X-4 Impose Output Important: all CMYK elements should be prepared for the same printing condition

6 PDF/X-4 (CMYK) creation Image and artwork Layout PDF/X-4 /X Export GWG2012 Check PDFX-ready V2 Issues creating compliant files X-4 : invalid XMP Metadata can be removed using Preflight tools X-4 :.notdef used for space character can be fixed using Preflight tools Tools need to be fixed PDF/X-4, PDFX-ready and Colour caused hours and hours of discussion ongoing process

7 clarification of print ready PDF/X-4 files File is prepared for one particular printing condition (defined by Output Intent) Focus on highest possible render consistency Focus on highest possible colour accuracy Any conversion (eg. to any other printing condition) can lead to a different rendering and is therefore outside the scope and is not supported!!! This is a general limitation of PDF PDF/X-4 and colour Which colour spaces are allowed? all Device colour spaces but DeviceRGB (assumption: Output Intent is CMYK) all calibrated colour spaces problematic colour definitions calibrated Gray - gets separated to CMYK calibrated CMYK - gets re-separated calibrated RGB - gets separated to CMYK. Works good for images, but not for line art -> GWG 2012 CMYK Variant Colour images DeviceCMYK DeviceGray DeviceRGB ICC based CMYK ICC based Gray ICC based RGB / Lab Colour text + vector DeviceCMYK DeviceGray DeviceRGB ICC based CMYK ICC based Gray ICC based RGB / Lab Transparency blend colour space Other features GWG 2012 CMYK data preparation variant PDF/X-1a PDF/X-4 CMYK NA DeviceCMYK / OutputIntent PDF/X-4 RGB Warning Warning DeviceCMYK / OutputIntent PDF/X-4 Full Anything

8 PDF/X-4 (ICC) creation Image and artwork Layout PDF/X-4 /X Export GWG201X ICC Check PDF/X-4 output use of native PDF renderer advantage of PDF renderer native PDF/X-4 Workflow PDF/X-4 Desktop Viewing /X Soft Proof Starting with X-4 requires native PDF rendering at every stage Hardcopy Proof Output

9 native PDF/X-4 Output the technology is out at Drupa 2008, Adobe announced Print Engine 2 (APPE) Harlequin Version 8 supports PDF1.6 EFI announced use of APPE at IPEX 2010 major (soft-)proofing software is based on native PDF rendering Why native PDF rendering? directly from PDF to image model of output device no flattening of transparency at any stage no unnecessary colour conversion possibility to use PDF functions that are not possible in other formats no intermediate format no loss of information no transformation to other object model possibility of colour mapping at the very latest stage Issues creating output of compliant files wrong settings Transparency flattening during input or processing in PDF Workflow use of first generation PDF rendering Tools need to be up to date with appropriate setup

10 What if output device does not handle PDF/X-4? Best: recreated PDF as PDF/X-1a Possibility 1: convert colour and flatten Possibility 2: render to image works best for low res output devices such as digital printing machines working with 600dpi PDF/X-4 processing trapping device link conversion layout using PDF/X-4 file PDF/X-4 and transparencies something to think about final colour in output is not necessarily the objects colour in the PDF Example: 50% gray in on plate can be defined as 100% Black having 50% transparency or a 50% transparent white object over a Black object colour conversion might lead to different visual appearance when using transparency typical usage: ink saving a PDF/X-4 file represents a digital master which should not be modified

11 Trapping object oriented trapping is only possible in output colour space (CMYK/Spot) works only partly on flattened files latest updates introduced trapping exceptions trapping of transparent objects less critical than expected colour of transparent objects usually mix with backdrop colour alternative solution: InRip Trapping DeviceLink Conversion DL conversion is only possible for known object colour Version 1: Colourserver takes into account transparency sometimes involves flattening still unsolved issue Version 2: support for DL profiles in PDF renderer on final rendered image only pages on an imposed sheet shall be converted, not the colour control objects reuse of PDF/X-4 in layout applications limited PDF/X support in layout applications for placed content OutputIntent is ignored OutputIntent must be same as Document colour space PDF/X-1a output causes the content of the placed PDF being flattened varying quality depending of used layout product

12 Repurpose PDF for tablet even there are issue preparing a print PDF for tablet (conversion to srgb, change of transparency group blend space to srgb), PDF/X-4 is the better format to start from PDFX-ready deliverables PDFX-ready deliverables Preflight Profiles NEW: PXR 2.0 originally based on draft version of GWG2012 spec 1 year beta phase Focus: CMYK variant released 1 year before GWG specification compatible with Acrobat 9 Preflight (not 100% conform to GWG 2012 Acrobat XI preflight profile in process PDFX-ready output test-form based on GWG Output test patches amalgamated onto one print form used for output certification

13 PDFX-ready deliverables PDFX-ready Leitfaden 52-page education material PXR V1 and PXR V2 - living side by side The PDF/X-standard Why PXR V2 image binding layout preparation PDF/X generation (CMYK variant) Preflighting PDF/X processing Colour Conversion Trapping Output PDFX-ready future work work in close cooperation with GWG RGB based variant for online publishing Variant for digital printing wide gamut version to carry more vivid colours output on wide gamut printing systems output for online publishing output for printing

14 Altona Test Suite 2, Technical (ATS 2) Focus: PDF/X-4 aspects Transparency and Transparency flattening Optional Content (Layers) JPEG2000 (also 16bit) OpenType ICC-v4-Profile each Patch is pre-rendered for easy analysis of rendering Principle: parted patches Life-Transparency and Reference-image upper half: Patch with transparent objects Transparenz+Spot patch lower half: pre-rendered image (expected result) -symbols mark reference-image 39 Principle: parted patches Life-Transparency and Reference-image left half: Patch with transparent objects Transparenz+Spot patch right half: pre-rendered image (expected result) -symbols mark reference-image 40

15 Transparency Drop-shadow Text: CMYK Image: CMYK Drop-shadow, two resolutions: left: high resolution (350 ppi) right: low resolution (36 ppi) 41 Drop-shadow with varying resolution Why did we do this? learning effect! Resolution of shadow is generated during PDF/ X-4 export (defined by transparency flattening presets). It is not possible to change this resolution after export. 42 possible s 43

16 possible errors colour management and transparency flattening Spot to CMYK: wrong sequence: 1. first flattening. SPOT to CMYK conversion 44 possible errors colour management and transparency rendering bad PDF rendering: ignoring ICCbasedRGB transparency blend space for isolated transparency group 45 Thank you Peter Kleinheider skype: gironimus mobil: