Choosing the software to drive your digital inkjet press

When developing your first or next digital press, the software you use to drive it will be a key factor in its success, both for the data rates and output quality you can achieve. The time it takes to get your press to market based on the engineering effort involved to deliver and integrate that software is also a consideration.

A simple user interface to get  you started

The Press Operator Controller (POC) is an example front end or user interface available with Harlequin Direct™ , the software solution that drives printhead electronics at ultra-high data rates while retaining high output quality. The POC provides you with an initial working system, so you’re up and running without any significant in-house software development. We provide you with the source code so that you have the option to update and integrate it as part of your production system.

I have created a short video to show you its main functions:

You can find out more information about the Direct™ range of products by visiting our website: https://www.globalgraphics.com/products/direct

Further reading about considerations when choosing your digital inkjet press:

  1. How do I choose the right PC specification for my digital press workflow
  2. Future-proofing your digital press to cope with rising data rates
  3. Looking to reduce errors with simple job management, keep control of color, and run at ultra-high speed for jobs with variable data?

About the author

Ian Bolton, Product Manager, Direct
Ian Bolton, Product Manager – Direct

Ian has over 15 years’ experience in industry as a software engineer focusing on high performance. With a passion for problem-solving, Ian’s role as product manager for the Direct range gives him the opportunity to work with printer OEMs and break down any new technology barriers that may be preventing them from reaching their digital printer’s full potential.

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How do I choose the right PC specification for my digital press workflow?

When planning the implementation of your first or next digital press, the PC specification you choose to run your software workflow will play an important part in the data rates you will be able to achieve. Assuming you are not bottlenecked by disk drive performance due to requiring intermediate disk accesses, you can generally expect data rates to rise with the computational power of your PC.

It might therefore make sense to review the PassMark scores for a range of CPUs within your budget and make your choice based on that, but this alone won’t be enough to tell you whether you’ll be able to drive your printer at full rated speed. Similarly, you may already have an existing PC system in mind but need to know if it will be powerful enough for your new requirements.

Ideally, you could set up an evaluation system to run some typical print jobs to get a definitive answer, but this could be costly and labor-intensive, especially if this is your first digital press.

It’s for this reason we created Direct Benchmark™: an analysis tool that exercises Harlequin Direct™, our ultra-high data rate RIPping and screening solution, with your choice of press configuration and print jobs, stepping through a tuning cycle to obtain a series of data rates and line speeds that can be achieved.

There are two main ways Direct Benchmark can help you: firstly, if you have an existing PC system to run on, you can install Direct Benchmark and gather your own results; secondly, you could base your decision on a database of Direct Benchmark results we are gathering here at Global Graphics Software from running a variety of jobs on a range of PC specifications.

Running Direct Benchmark yourself

Whilst a real Harlequin Direct system would be connected to printhead electronics and driving your press directly, the Harlequin Direct invoked by Direct Benchmark doesn’t require this connection. This makes it very quick and easy to install and start gathering performance numbers. The screenshot below shows the settings you can use to reflect your printer configuration and define the print jobs to benchmark.

During benchmarking, you will be presented with a screen showing statistics for each run and a real-time graph of data rate at the bottom, and then you will be able to export the results at the end. If you would like to see Direct Benchmark in action, you can view a short demo here:

Using the Direct Benchmark database

If you aren’t in a position to run Direct Benchmark yourself, we are in the process of gathering results for a range of press configurations and print jobs, running on a variety of PC hardware specifications. This is being conducted in conjunction with Proactive Technologies, who are providing access to some of the machines we’re using. Whilst it is too early to draw any conclusions or share our results at this stage, if you have some typical print jobs and a press configuration in mind, please get in touch with me, ian.bolton@globalgraphics.com, because we may be able to generate the results for you.

For more information about Direct, please visit globalgraphics.com/direct

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About the author:

Ian Bolton, Product Manager, Direct
Ian Bolton, Product Manager – Direct

Ian has over 15 years’ experience in industry as a software engineer focusing on high performance. With a passion for problem-solving, Ian’s role as product manager for the Direct range gives him the opportunity to work with printer OEMs and break down any new technology barriers that may be preventing them from reaching their digital printer’s full potential.

 

Why does optimization of VDP jobs matter?

Would you fill your brand-new Ferrari with cheap and inferior fuel? It’s a question posed by Martin Bailey in his new guide: ‘Full Speed Ahead – how to make variable data PDF files that won’t slow your digital press’. It’s an analogy he uses to explain the importance of putting well-constructed PDF files through your DFE so that they don’t disrupt the printing process and the DFE runs as efficiently as possible. 

Here are Martin’s recommendations to help you avoid making jobs that delay the printing process, so you can be assured that you’ll meet your print deadline reliably and achieve your printing goals effectively:

If you’re printing work that doesn’t make use of variable data on a digital press, you’re probably producing short runs. If you weren’t, you’d be more likely to choose an offset or flexo press instead. But “short runs” very rarely means a single copy.

Let’s assume that you’re printing, for example, 50 copies of a series of booklets, or of an imposed form of labels. In this case the DFE on your digital press only needs to RIP each PDF page once.

To continue the example, let’s assume that you’re printing on a press that can produce 100 pages per minute (or the equivalent area for labels etc.). If all your jobs are 50 copies long, you therefore need to RIP jobs at only two pages per minute (100ppm/50 copies). Once a job is fully RIPped and the copies are running on press you have plenty of time to get the next job prepared before the current one clears the press.

But VDP jobs place additional demands on the processing power available in a DFE because most pages are different to every other page and must therefore each be RIPped separately. If you’re printing at 100 pages per minute the DFE must RIP at 100 pages per minute; fifty times faster than it needed to process for fifty copies of a static job.

Each minor inefficiency in a VDP job will often only add between a few milliseconds and a second or two to the processing of each page, but those times need to be multiplied up by the number of pages in the job. An individual delay of half a second on every page of a 10,000-page job adds up to around an hour and a half for the whole job. For a really big job of a million pages it only takes an extra tenth of a second per page to add 24 hours to the total processing time.

If you’re printing at 120ppm the DFE must process each page in an average of half a second or less to keep up with the press. The fastest continuous feed inkjet presses at the time of writing are capable of printing an area equivalent to over 13,000 pages per minute, which means each page must be processed in just over 4ms. It doesn’t take much of a slow-down to start impacting throughput.

If you’re involved in this kind of calculation you may find the digital press data rate calculator at https://blog.globalgraphics.com/tag/data-rate/ useful:

Global Graphics Software’s digital press data rate calculator.
Global Graphics Software’s digital press data rate calculator.

This extra load has led DFE builders to develop a variety of optimizations. Most of these work by reducing the amount of data that must be RIPped. But even with those optimizations a complex VDP job typically requires significantly more processing power than a ‘static’ job where every copy is the same.

The amount of processing required to prepare a PDF file for print in a DFE can vary hugely without affecting the visual appearance of the printed result, depending on how it is constructed.

Poorly constructed PDF files can therefore impact a print service provider in one or both of two ways:

  • Output is not achieved at engine speed, reducing return on investment (ROI) because fewer jobs can be produced per shift. In extreme cases when printing on a continuous feed (web-fed) press a failure to deliver rasters for printing fast enough can also lead to media wastage and may confuse in-line or near-line finishing.
  • In order to compensate for jobs that take longer to process in the DFE, press vendors often provide more hardware to expand the processing capability, increasing the bill of materials, and therefore the capital cost of the DFE.

Once the press is installed and running the production manager will usually calculate and tune their understanding of how many jobs of what type can be printed in a shift. Customer services representatives work to ensure that customer expectations are set appropriately, and the company falls into a regular pattern. Most jobs are quoted on an acceptable turn-round time and delivered on schedule.

Depending on how many presses the print site has, and how they are connected to one or more DFEs this may lead to a press sitting idle, waiting for pages to print. It may also delay other jobs in the queue or mean that they must be moved to a different press. Moving jobs at the last minute may not be easy if the presses available are not identical. Different presses may require different print streams or imposition and there may be limitations on stock availability, etc.

Many jobs have tight deadlines on delivery schedules; they may need to be ready for a specific time, with penalties for late delivery, or the potential for reduced return for the marketing department behind a direct mail campaign. Brand owners may be ordering labels or cartons on a just in time (JIT) plan, and there may be consequences for late delivery ranging from an annoyed customer to penalty clauses being invoked.

Those problems for the print service provider percolate upstream to brand owners and other groups commissioning digital print. Producing an inefficiently constructed PDF file will increase the risk that your job will not be delivered by the expected time.

You shouldn’t take these recommendations as suggesting that the DFE on any press is inadequate. Think of it as the equivalent of a suggestion that you should not fill your brand-new Ferrari with cheap and inferior fuel!

 

Full Speed Ahead: how to make variable data PDF files that won't slow your digital press edited by Global Graphics Software

The above is an excerpt from Full Speed Ahead: how to make variable data PDF files that won’t slow your digital press. The guide is designed to help you avoid making jobs that disrupt and delay the printing process, increasing the probability of everyone involved in delivering the printed piece; hitting their deadlines reliably and achieving their goals effectively.

DOWNLOAD THE FREE FULL GUIDE HERE: https://bit.ly/fsa-pdf

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About the author:

Martin Bailey, CTO, Global Graphics Software
Martin Bailey, CTO, Global Graphics Software

Martin Bailey first joined what has now become Global Graphics Software in the early nineties, and has worked in customer support, development and product management for the Harlequin RIP as well as becoming the company’s Chief Technology Officer. During that time he’s also been actively involved in a number of print-related standards activities, including chairing CIP4, CGATS and the ISO PDF/X committee. He’s currently the primary UK expert to the ISO committees maintaining and developing PDF and PDF/VT.

Harlequin RIP gains Ghent PDF Output Suite 5 compliancy

We’ve just added the Harlequin RIP® to the list of products certified as compliant with the Ghent Workgroup’s Output Suite 5 at https://www.gwg.org/ghent-pdf-output-suite-5-compliancy/

It was an interesting exercise, not because it was difficult, but because we started with a bit of archaeology. Back in February 2003 we published an “Application Data Sheet” of instructions for configuring versions 5.3 and 5.5 of the Harlequin RIP to render PDF/X-1a files. We followed that up with another edition for Harlequin 6 (the Eclipse release), addressing PDF/X-3 as well in 2004, and then for Harlequin 7 (Genesis) in 2005.

After that it seemed that PDF/X was sufficiently well understood and so widely adopted in the marketplace that we didn’t need to continue the series. Added to that, we’d added the ability for Harlequin RIPs to recognize PDF/X files and automatically change the RIP configuration around things like overprinting to, as we phrased it at the time, “Do the Right Thing™”.

So when we started writing up how to configure Harlequin for the GWG Output Suite we simply opened up the 2005 doc and replaced the screen grab of the user interface in Harlequin MultiRIP with a one from Harlequin 12.1. In 14 years we’ve added a few options, and, of course, a Windows 10 dialog looks a bit different to one from Windows XP!

We did have to add a couple of extra bullet points to the instructions, especially around perfecting the color management of spots being emulated in process colorants. Some of our color focus over the last decade has been on outputting to a fixed ink set, whether that’s on a digital press or for flexo or offset. So we made the point by delivering our sample output to be reviewed by the GWG as a CMYK raster file … and yes, all of the spot colors in the test suite showed up correctly in their emulations, it all passed 100%.

But that was it.

We thought about adding an indication of which RIP versions the instructions applied to, but ended up simply pointing out when a configuration item had been changed from a check-box to a three-way drop-down menu. The instructions will give you good output from all Harlequin RIPs shipped by Global Graphics in the last decade, and into the future as well.

I love it when stuff just works, and continues to just work, like this. There’s definitely a benefit to aiming to Do the Right Thing™!

Harlequin RIP® gains Ghent PDF Output Suite 5 compliancy
Harlequin RIP® gains Ghent PDF Output Suite 5 compliancy

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Future-proofing your digital press to cope with rising data rates

When we hear the phrase “big data”, we’re meant to think of extremely large data sets that are too complex to process in traditional ways. But, in the context of the next generation of digital presses, you’d be forgiven for thinking it refers to the ultra-high data rates required to drive them.

For example, consider a typical narrow-web label press: 13 inches (330mm) wide, 4 colors, 600x600dpi, running at 230 fpm (70m/min). This requires 0.9 GB/s of raster data to drive it at its rated speed.

Assuming next year’s press adds three more colors (Orange, Green and White) and is upgraded to 1200x1200dpi and expected to run a little faster at 330 fpm (100m/min), the required data rate will jump to 8.6 GB/s: almost a factor of ten increase!

Already this is a data rate far in excess of what the fastest solid-state drives can manage, so what hope is there for a traditional disk-based workflow when moving to 20 inches wide, duplex or 200m/min? Clearly, any part of the workflow involving a disk drive is going to become a bottleneck.

Ditch the disk with Direct
Ditch the disk. Rather than write intermediate raster files to disk between RIPping and screening, or between screening and the printhead electronics, everything takes place in memory.

This was one of the reasons behind the creation of Direct™, the integrated software pipeline we announced at the end of April. Rather than write intermediate raster files to disk between RIPping and screening, or between screening and the printhead electronics, everything takes place in memory.

There’s more to future-proofing your press than eliminating comparatively slow disk accesses, however. You’ll need a system that’s scalable and built from the fastest components, which is why Harlequin Direct™ is composed from a configurable number of Harlequin Host Renderer™ and ScreenPro™ instances working in parallel to make the best of the most powerful desktop PCs available.

When it comes to adding new colors or supporting duplex, the scalability extends to multiple Harlequin Directs across multiple PCs, one per print bar.

When it comes to adding new colors or supporting duplex, the scalability extends to multiple Harlequin Directs across multiple PCs, one per printbar.

An added advantage of this approach is that each printbar need not use the same resolution or drop-count etc. For example, you might wish to use a lower resolution and disable color management for white or varnish. Our Press Operator Controller user interface is supplied to manage your configuration, along with submitting and controlling your print jobs.

Our Press Operator Controller user interface is supplied to manage your configuration, along with submitting and controlling your print jobs.

The beauty of a software-only solution like Direct is that once you have built it into your workflow, you are free to upgrade your PCs over time for greater performance without any further software integration expense. A Direct-based system will evolve as your needs evolve, making it the ideal choice for future-proofing your next digital press.

For more information about Direct, please visit globalgraphics.com/direct.

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Ian Bolton, Product Manager, Direct
Ian Bolton, Product Manager, Direct

About the author:
Ian has over 15 years’ experience in industry as a software engineer focusing on high performance. With a passion for problem-solving, Ian’s role as product manager for the Direct range gives him the opportunity to work with printer OEMs and break down any new technology barriers that may be preventing them from reaching their digital printer’s full potential.

Mako™ – the print developer’s Swiss Army knife

Mako - the Swiss Army knife of SDKs!
Mako – the print developer’s Swiss Army knife.

Working with a Mako customer recently, I showed him how to code a utility to extract data from a stack of PDF invoices to populate a spreadsheet. I suppose you could describe it as reverse database publishing. This customer had originally licensed Mako to convert XPS to PDF, and later used it to generate CMYK bitmaps of the pages, i.e. using it as a RIP (raster image processor).

With this additional application of Mako, the customer observed that Mako was “like a Swiss Army knife” as it offered so many tools in one – converting, rendering, extracting, combining and processing, of pages and the components that made them up. And doing it not just for PDF but for XPS, PCL and PostScript® too. His description struck a chord with me as it seemed very appropriate. Mako does indeed offer a wide range of capabilities for processing print job formats. It’s not the fastest or feature-richest of the RIPs from Global Graphics Software – that would be Harlequin®. Or the most sophisticated and performant of screening tools – that would be ScreenPro™. But Mako can do both of those things very competently, and much more besides.

For example, we have used Mako to create a Windows desktop app to edit a PDF in ways relevant to production print workflows, such as changing spot colors or converting them to process colors. All the viewing and editing operations are implemented with Mako API calls. That fact alone emphasizes the wide range of applications to which Mako can be put, and I think, fully justifying that “Swiss Army knife” moniker.

For more information visit: www.globalgraphics.com/mako

RIP technology replacement achieves a faster development time, performance and quality benchmarks

 VIR Softech replaces RIP software for major print OEM and achieves a faster development time, performance and quality benchmarks

When a major print OEM switched from a market-leading RIP technology to the Harlequin RIP®, they achieved a faster development time and performance and quality benchmarks with a reduced bill of materials cost.

The Challenge
When a leading print OEM was looking to move to a PDF RIP technology that was easy to integrate and help to achieve quality and performance benchmarks, it contacted Global Graphics Software Partner Network member, Vir Softech. As a RIP replacement service provider, the team at Vir Softech includes experienced engineers, with experts who have worked on all the major RIP technologies and understand the interfaces and functions they offer.

The Solution
Vir Softech recommended switching from the existing RIP technology to the Harlequin RIP from Global Graphics Software. Vir Softech had experience of using the Harlequin RIP in a similar project and knew it would meet the print OEM’s requirements. After a period of evaluation, including quality and performance benchmarking, the print OEM chose to use the Harlequin RIP.

Deepak Garg, managing director at Vir Softech explains the process: “The first step towards making the change was to assess and understand the various features and functions offered by the OEM’s print devices.”

After investigating, the team prepared a design document highlighting:

  • The OEM’s product features that interact with the RIP technology
  • How these product features are implemented
  • The various RIP interfaces which are used to implement these features and functions

Deepak continues: “Once the print OEM decided to go ahead, we prepared another document highlighting how to achieve these functions using the Harlequin interfaces. Some functions or features could not be implemented using Harlequin directly, such as special color handling, spot color replacement, extraction of cut data etc., so we contacted Global Graphics Software who was able to provide a design showing how these functions could be implemented using Harlequin. We then prepared a proof-of-concept, or working implementation, which demonstrated how the Harlequin RIP would work with the print OEM’s print devices. With Harlequin, such a prototype can usually be achieved within three to six months.”

The Result
Development time was much shorter than usual for such an ambitious undertaking, greatly reducing costs and enabling the print OEM to drive their revenue earlier than originally expected. The print OEM began using the Harlequin RIP, instantly meeting its quality and performance targets.

The print OEM says: “The Harlequin RIP helped us to move to native PDF printing and achieve the performance targets for our printers. Harlequin also helped us to reduce the lead time for getting our products to market while keeping development and maintenance costs low.”

About Vir Softech
Vir Softech is a technology start-up with expertise in imaging and computer vision technologies. With a strong focus in the Print & Publishing domain, its team of experienced engineers includes experts in all aspects of imaging and RIP technologies, such as job management, job settings, color management, screening, bands generation and management, VDP and imposition etc.

The team at Vir Softech are experts in configuring RIP technologies for better performance targeted for a specific market segment such as production, commercial, large format and enterprise printing. Some of the areas where Vir Softech can help include low resource environment, implementing OEM-specific unique functions using Harlequin RIP interfaces, making use of OEM ASIC for better performance, making use of OEM hardware accelerators for some of the computer-intensive RIP operations such as color conversion, image transformations, image decoding, rendering etc and achieving PPM target of MFP for ISO test suites.

To find out more visit: www.virsoftech.com

 

 

 

PDF Processing Steps – the next evolution in handling technical marks

Best practice in handling jobs containing both real graphic content and ‘technical marks’ has evolved over the last couple of decades. Technical marks include things like cut/die lines, fold lines, dimensions, legends etc in a page description language file (usually PDF these days). Much of the time, especially for pouches, folding carton and corrugated work, they’ll come originally from a CAD file and will have been merged with the graphics.

People will want to interact with the technical marks differently at various stages in the workflow:

  • Your CAD specialists will want to see the technical marks and make sure that they’ve not been changed from the original CAD input.
  • Brand owner approval may not want to see the technical marks, but prepress and production manager approvers will definitely want to see both the technical marks and the graphics together on their monitors, with the ability to make layers visible or invisible at will.
  • In some workflows the technical marks from the PDF may be used to make a physical die, or to drive a laser cutter; in others an original CAD file will be used instead.
  • On a digital press you may wish to print a short run of just the technical marks, or a combination of technical marks and graphics to ensure that finishing is properly registered with the prints.
  • The main print run, whether on a conventional press (flexo, offset, etc) or digital, will obviously include the graphics, but won’t include most of the technical marks. You may want to include the legend on the print as fool-proof identification of that job, but you’ll obviously need to disable printing of any marks that overlap with the live area or bleed, such as cut and fold marks.
  • Occasionally you may wish to do another short run with technical marks after the main print run, to ensure that finishing has not drifted out of register.

So there are a lot of places in the entire process where both technical marks and graphics may need to be turned on or off. How do you do that in your RIP?

Historically, the first method used to include technical marks, originally in PostScript, but now also in PDF, was to specify each kind of technical mark in a ‘technical separation’, encoded as a spot color in the job. Most operators tried to use a name for that spot color that indicated its intent, but there weren’t any standards, so you could end up with ‘Cut’ (or ‘CUT’, ‘cut’ etc), ‘cut-line’, ‘cut line’, ‘cutline’, ‘die’ etc etc. And that’s just thinking about naming in English. The names chosen are usually fairly meaningful to a human operator, but couldn’t be used reliably for automated processing because of the amount of variation.

As a result, many jobs arriving at a converter, at least from outside of that company, must be reviewed, and the spot names replaced, or the prepress and RIP configured to use the names from that job. That manual processing takes time and introduces the potential for errors.

But let’s assume you’ve completed that stage; how do you configure your RIP to achieve what you need with those technical separations?

The most obvious mechanism to turn off some technical marks is to tell the RIP to render the relevant spot colors as their own separations, but then not to image them on the print. It’s a very simple model, which works well as long as the job was constructed correctly, with all of the technical marks set to overprint. When somebody upstream forgot and left a cut or fold line as knockout (which never happens, of course!) you’d get a white line through the real graphics if the technical mark was on top of them.

The next evolution of that would be to configure the RIP to say that the nominated spot separation should never knock out of any other separation. That’s a configuration option in Harlequin RIPs but may not be widely available elsewhere.

Or you could tell the RIP to completely ignore one or more nominated spot colors, so they have no effect at all on any other marks on the page. Again, that’s a configuration option in Harlequin RIPs, and is one of the best ways of managing technical marks that are saved into the PDF file as technical separations.

Alternatively, since technical marks (like many other parts of a label or packaging job) are usually captured in a PDF layer (or optional content group to use the technical term), you can turn those layers on and off. Again, there are rich controls for managing PDF layers in Harlequin RIPs.

But none of these techniques get away from the need to manually check each file and set up prepress and the RIP appropriately for the spot names or layers that have been used for technical marks.

And that’s where the new ISO standard, 19593-1:2018 comes in. It defines “PDF processing Steps”, a mechanism to uniquely identify technical marks in PDF files, along with their intended function, from cutting to folding and creasing, to bleed areas, white and varnish, braille, dimensions, legends etc. It does this by building on the common practice of saving the technical marks in PDF layers, but adds some identification metadata that is not dependent on the vendor, the language or the normal practice of the originator, prepress or pressroom.

So now you can look at a PDF file and see definitively that a layer called ‘cut’ contains cutting lines. The name ‘cut’ is now just a convenience; the real information is in metadata which is completely and reliably computer-readable. In other words, it doesn’t matter if that layer were named ‘Schnittlinie’ or anything else; the manual step of identifying names that someone, somewhere put in the file upstream and figuring out what each one means, is completely eliminated.

We implemented support for PDF Processing Steps into version 12.1r0 of the Harlequin RIP, and have worked with a number of vendors whose products create files with Processing Steps in them (including Hybrid Software, Esko and Callas) to ensure that everything works seamlessly. We also worked through a wide variety of current and probable use cases to ensure that our implementation can address real-world needs. As an example we added the ability to control all graphics on a PDF page that aren’t in Processing Step layers as if they were just another layer.

In practice this means that Harlequin can be configured to deliver pretty much whatever you need, such as:

  • Export all technical marks identified as Cutting, PartialCutting, CuttingCreasing etc to a vector format to drive a cutting machine.
  • Render and print all technical marks, but none of the real graphics, for checking registration.
  • Render the real graphics, plus dimensions and legend, for the main print run.

    PDF Processing Steps promises the ability to control technical marks without needing to analyze each file and create a different setup for each job.
    PDF Processing Steps promises the ability to control technical marks without needing to analyze each file and create a different setup for each job.

The most important thing that PDF Processing Steps gives us is that you can create a configuration for one of those use cases (or for many other variations) and know that it will work for all jobs that are sent to you using PDF Processing Steps; you won’t need to reconfigure for the next job, just because an operator used different spot names.

Of course, it’ll take a while for everyone to migrate from using spot names to PDF Processing Steps. But I think you’ll agree that the benefits of doing so, in increasing efficiency and reducing the potential for errors, are obvious and significant.

For more information read the press release here.

Choosing the class of your raster image processor (RIP) – Part II

Part II: Factors influencing your choice of integration

If you’re in the process of building a digital front end for your press, you’ll need to consider how much RIPing power you need for the capabilities of the press and the kinds of jobs that will be run on it. The RIP converts text and image data from many file formats including PDF, TIFF™ or JPEG into a format that a printing device such as an inkjet print head, toner marking engine or laser plate-setter can understand. But how do you know what RIP is best for you and what solution can best deliver maximum throughput on your output device? In this second post, Global Graphics Software’s CTO, Martin Bailey, discusses the factors to consider when choosing a RIP.

In my last post I gave a pointer to a spreadsheet that can be used to calculate the data rate required for a digital press. This single number can be used to make a first approximation of which class of RIP integration you should be considering.

For integrations based on the Harlequin RIP® reasonable guidelines are:

  • Up to 250MB/s: can be done with a single RIP using multi-threading in that RIP
  • Up to 1GB/s: use multiple RIPs on a single server using the Harlequin Scalable RIP
  • Over 1GB/s: use multiple RIPs spread over multiple servers using the Harlequin Scalable RIP

These numbers indicate the data rate that the RIP needs to provide when every copy of the output is different. The value may need to be adjusted for other scenarios:

  • If you’re printing the same raster many times, the RIP data rate may be reduced in proportion; the RIP has 100 times as long to process a PDF page if you’re going to be printing 100 copies of it, for instance.
  • If you’re printing variable data print jobs with significant re-use of graphical elements between copies, then Harlequin VariData™ can be used to accelerate processing. This effect is already factored into the recommendations above.

The complexity of the jobs you’re rendering will also have an impact.

Transactional or industrial labelling jobs, for example, tend to be very simple, with virtually no live PDF transparency and relatively low image coverage. They are therefore typically fast to render. If your data rate calculation puts you just above a threshold in the list above, you may be able to take one step down to a simpler system.

On the other hand, jobs such as complex marketing designs or photobooks are very image-heavy and tend to use a lot of live transparency. If your data rate is just below a threshold on the list above, you will probably need to step up to a higher level of system.

But be careful when making those adjustments, however. If you do so you may have to choose either to build and support multiple variations of your DFE, to support different classes of print site, or to design a single model of DFE that can cope with the needs of the great majority of your customers. Building a single model certainly reduces development, test and support costs, and may reduce your average bill of materials. But doing that also tends to mean that you will need to base your design on the raw, “every copy different”, data rate requirements, because somebody, somewhere will expect to be able to use your press to do just that.

Our experience has also been that the complexity of jobs in any particular sector is increasing over time, and the run lengths that people will want to print are shortening. Designing for current expectations may give you an under-powered solution in a few years’ time, maybe even by the time you ship your first digital press. Moore’s law, that computers will continue to deliver higher and higher performance at about the same price point, will cancel out some of that effect, but usually not all of it.

And if your next press will print with more inks, at a higher resolution, and at higher speed you may be surprised at how much impact that combination will have on the data rate requirements, and therefore possibly on the whole architecture of the Digital Front End to drive it.

And finally, the recommendations above implicitly assume that a suitable computer configuration is used. You won’t achieve 1GB/s output from multiple RIPs on a computer with a single, four-core CPU, for example. Key aspects of hardware affecting speed are: number of cores, CPU clock speed, disk space available, RAM available, disk read and write speed, band-width to memory, L2 and L3 cache sizes on the CPU and (especially for multi-server configurations) network speed and bandwidth.

Fortunately, the latest version of the Harlequin RIP offers a framework that can help you to meet all these requirements. It offers a complete scale of solutions from a single RIP through multiple RIPs on a single server, up to multiple RIPs across multiple servers.

 

The above is an excerpt from our latest white paper: Scalable performance with the Harlequin RIP. Download the white paper here.

Read Part I – Calculating data rates here.

What does a Raster Image Processor (RIP) do?

Ever wondered what a raster image processor or RIP does? And what does RIPing a page mean? Read on to learn more about the phases of a RIP, the engine at the heart of your Digital Front End.

The RIP converts text and image data from many file formats including PDF, TIFF™ or JPEG into a format that a printing device such as an inkjet print head, toner marking engine or laser platesetter can understand. The process of RIPing a page requires several steps to be performed in order, regardless of whether that page is submitted as PostScript, PDF or any other page description language.

Interpreting: the page description language to be RIPed is read and decoded into an internal database of graphical elements that must be placed on the page. Each may be an image, a character of text (including font, size, color etc), a fill or stroke etc. This database is referred to as a display list.

Compositing: The display list is pre-processed to apply any live transparency that may be in the job. This phase is only required for any pages in PDF and XPS jobs that use live transparency; it’s not required for PostScript language pages because those cannot include live transparency.

Rendering: The display list is processed to convert every graphical element into the appropriate pattern of pixels to form the output raster. The term ‘rendering’ is sometimes used specifically for this part of the overall processing, and sometimes to describe the whole of the RIPing process. It’s only used it in the first sense in this document.

Output: the raster produced by the rendering process is sent to the marking engine in the output device, whether it’s exposing a plate, a drum for marking with toner, an inkjet head or any other technology.

Sometimes this step is completely decoupled from the RIP, perhaps because plate images are stored as TIFF files and then sent to a CTP platesetter later, or because a near-line or off-line RIP is used for a digital press. In other environments the output stage is tightly coupled with rendering.

RIPing often includes a number of additional processes; in the Harlequin RIP® for example:

  • In-RIP imposition is performed during interpretation
  • Color management (Harlequin ColorPro®) and calibration are applied during interpretation or compositing, depending on configuration and job content
  • Screening is applied during rendering or after the Harlequin RIP has delivered unscreened raster data if screening is being applied post- RIP, when Global Graphics’ ScreenPro™ and PrintFlat™ technologies are being used, for example.

These are all important processes in many print workflows.

 

The Harlequin Host Renderer
The Harlequin RIP includes native interpretation of PostScript, EPS, DCS, XPS, JPEG, BMP and TIFF as well as PDF, PDF/X and PDF/VT, so whatever workflows your target market uses, it gives accurate and predictable image output time after time.

The above is an excerpt from our latest white paper: Scalability with the Harlequin RIP®.

Scalable performance with the Harlequin RIP

Download the white paper here

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