Shade and color variation in textile printing – why it’s important and what you can do about it

Printing soft furnishings

With fewer design limitations, a faster turnaround, no minimum run length and higher margins (not to mention reduced use of power and water, and of pollution), it’s not surprising that the digitally printed textile market is growing.1 Inkjet has certainly made textile design and printing much more flexible than screen printing – and that goes for everybody involved, from the designer through the printing company, to the buyer.

But printing textiles on inkjet doesn’t come without its challenges: as a software provider focusing on print quality issues, we often hear from print service providers who can only digitally print two thirds of the jobs they receive because they would not be paid for the quality they could achieve on the others.

Shade or color variation is a common problem. It’s not new in digital printing (it’s always been an issue for screen-printed and dyed textiles as well) and is usually managed by providing a shade band, which printer operators refer to, to check allowable color variations between pieces.

But, unlike screen-printing or dyeing, the color variation on an inkjet press can be visible over a small distance, just a few centimeters, and this results in visible bands across the output. Banding describes features that tend to be 1 – 10 cm across and they’re often caused by variation of inkjet pressure or voltage differences within the head, which typically results in a frown or smile shape. We also see a certain amount of manufacturing variation between heads so that one may print lighter or darker than the head next to it in a print bar. Some types of heads can also wear in use, which can result in less regular banding that can change over time. This means that large areas which should be flat color may not be.

When such a variation occurs it can greatly complicate a lot of post-print steps, especially if you need to put more than one piece of textile together, either in sewing or use (such as a pair of curtains). If that’s the case, then a significant difference may be unacceptable and your printing rejected by your buyer. Ultimately this leads to print service providers rejecting jobs, because they know their digital press can’t handle printing those tricky flat tints or smooth tones.

What can you do about it?

The first thing many companies do to try to overcome this banding is to adjust the voltage to the inkjet head, but this is often time-consuming and expensive because it requires an expert technician. A better alternative is to make the correction in software, which is a more cost-effective and faster solution. It means it can be automated and can act at a much finer granularity, so printing is more accurate. There’s no need to mess with controls that could damage the press, and printing companies themselves can make corrections without the vendor sending a technician on-site.

Our solution at Global Graphics Software for improving banding is PrintFlat™. It corrects tonality to hide banding based on measurements from the press. It adjusts every nozzle separately and doesn’t need a specialist engineer to make press adjustments. PrintFlat can be integrated into different digital front ends, using a variety of RIPs, including Caldera and Colorgate and, not to mention, our own Harlequin RIP®.

Over the years of working with many press manufacturers we’ve discovered that many technical issues and solutions are common across different sectors, including transactional, wide-format, commercial, labels and packaging, and industrial, including ceramics, wall coverings, flooring and of course textiles. That means that we already have years of experience in correcting for banding. Using PrintFlat in your press means print service providers can now take on those jobs they would normally reject.

To learn more about how to eliminate shade and color variation when printing on an inkjet press, listen to Global Graphics Software’s CTO Martin Bailey’s talk for FESPA 2020:

“New techniques to eliminate in-lot shade variation when printing textiles with inkjet.”

Or visit the PrintFlat website: https://www.printflat.com/

Further reading:

  1. What causes banding in inkjet? (And the smart software solution to fix it.)
  2. Streaks and Banding: Measuring macro uniformity in the context of optimization processes for inkjet printing

To be the first to receive our blog posts, news updates and product news why not subscribe to our monthly newsletter? Subscribe here

Follow us on LinkedIn and Twitter

_______________________________

  1. Digitally printed textiles are estimated to be between 2% – 5% of the total printed textiles market. Estimated at $146.5 billion in 2018 by Grand View Research

What’s the best effective photographic image resolution for your variable data print jobs?

It goes without saying that the final quality of your printed piece is paramount. But when speed and time constraints are also critical, what can you do to ensure your files fly through the press and still reward you with the quality you expect? Optimizing the images in the piece is a good place to start, but if you’re creating a job with variable data, where there are thousands of pages to print, each with a different image, how do you know what a sensible effective resolution is for those images that will ensure your PDF file doesn’t trip up the print production workflow?

In his latest guide, Full Speed Ahead, how to make variable data PDF files that won’t slow your digital press, Martin Bailey, CTO at Global Graphics Software, advises not to ask the print workflow to do more work than necessary if that doesn’t change the look of the printed result. Images are commonly re-used within a VDP job, so being able to process each image only once and then re-use the result many times can significantly increase the throughput of the digital front end. On the other hand, some images are personal to every recipient and must therefore be processed for every single recipient, slowing the workflow down.

Martin offers the following tips for setting appropriate effective photographic image resolutions:

  1. Aim for 300 ppi, however the most appropriate image resolution for digital presses varies, depending on printing heads, media and screening used.
  2. Bear in mind image content; soft and dreamy images can be sometimes placed at a lower resolution.
  3. Don’t use a higher effective image resolution for photographic images than the output resolution as this is often not productive. The example in Fig 1 below illustrates how easy it is to use an image at several times the required resolution:

The same 12-megapixel image at 3 different sizes

Fig 1: The same 12-megapixel (4000 x 3000 px) image placed on the page at three different sizes. Source: Full Speed Ahead, how to make variable data PDF files that won’t slow your digital press.

When an image is placed onto a page the original resolution of that image is largely irrelevant; what matters is how many pixels there are per inch on the final printed page. As an example, if you have a photograph from a 12 MP compact camera it’ll probably be approximately 3000 pixels by 4000 pixels. If that’s placed on the page as 3 inches by 4 inches (7.5 x 10cm) the effective resolution is about 1000ppi (4000/4). That would usually be about three times as much as you need in each dimension.

A variety of tools are available for optimizing image resolution, and some composition tools can also do this automatically. To find out more about the best effective resolution for your images, and to pick up more tips for optimizing your images for variable data printing, download the guide:

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

Full Speed Ahead – how to make variable data PDF files that won’t slow your digital press.

Be the first to receive our blog posts, news updates and product news. Why not subscribe to our monthly newsletter? Subscribe here

Follow us on LinkedIn and Twitter

 

Carry out complex tasks for your print workflow easily with Mako SDK

If you’re into code, then you’ll enjoy watching the recording of our recent webinar, Sharpen the saw: a live coding demo using Mako™.

Mako is a versatile SDK for building fast, scalable solutions for your print workflow. Its unique document object model uses Mako’s C++ and C# APIs to control color, fonts, text, images, vector content, metadata and more, combining precision with performance.

In the session, principal engineer Andy Cardy uses coding in C++ and C# to show you three complex tasks that you can easily achieve with Mako:

  • PDF rendering
  • Using Mako in Cloud-ready frameworks
  • Analyzing and editing with the Mako Document Object Model

Look out for more sessions like this over the coming months.

Watch it here:

For more information about Mako, please visit globalgraphics.com/mako

Be the first to receive our blog posts, news updates and product news. Why not subscribe to our monthly newsletter? Subscribe here

Follow us on LinkedIn and Twitter

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

To be the first to receive our blog posts, news updates and product news why not subscribe to our monthly newsletter? Subscribe here

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.

 

To be the first to receive our blog posts, news updates and product news why not subscribe to our monthly newsletter? Subscribe here

Follow us on LinkedIn and Twitter

Full Speed Ahead: How to make variable data PDF files that won’t slow your digital press

The use of variable data has increased exponentially over the past five years and is emerging in new applications such as industrial inkjet. Yet poorly designed variable data PDF files disrupt production and reduce ROI.

Watch the recent webinar with Global Graphics Software’s CTO Martin Bailey, the author of Full Speed Ahead, a new guide to offer advice to anyone with a stake in variable data printing, including graphic designers, print buyers, production managers, press operators, composition tool developers and users.

In the webinar Martin presents an overview of the guide and highlights some of the key tips and tricks for graphic designers, prepress and print service providers, showing how, when they all work together, VDP jobs can fly through digital presses.

Sponsored by Delphax Solutions, Digimarc, HP Indigo, HP PageWide Industrial, HYBRID Software, Kodak, Racami and WhatTheyThink, the guide is a practical format for easy reference and includes:

• Tips and tricks for making fast, efficient PDF files for variable data printing
• Helpful illustrations, photos and explanatory diagrams
• Real examples from industry

You can download your copy here: https://www.globalgraphics.com/full-speed-ahead

For further reading about PDF documents and standards:

  1. PDF Processing Steps – the next evolution in handling technical marks

To be the first to receive our blog posts, news updates and product news why not subscribe to our monthly newsletter? Subscribe here

Follow us on LinkedIn and Twitter

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

 

 

 

Improve inkjet output quality with PrintFlat™

If you print on an inkjet press you’ll know that the problem of non-uniformity or banding is a particularly difficult one to resolve. It’s especially acute on areas of flat tints with the result that printed output is unacceptable to you and to your customers. This means you either don’t run certain jobs on your inkjet press or, in some sectors of the market, are forced to sell your output at a discount.

The good news is that with PrintFlat you have a solution that is quick to deploy and cost-effective, and it can be applied to any workflow with or without a RIP. With more press vendors adopting this technology, watch our new explainer video to see how you might benefit.

Find out more about PrintFlat here.

 

Looking to reduce errors with simple job management, keep control of color, and run at ultra-high speed for jobs with variable data?

With just a few days to Labelexpo Europe 2019, preparation is in full swing. Come along to booth 9A15 where we’ll be previewing a new version of Fundamentals™, our toolkit for building a digital front end.

Fundamentals is a collaboration between Global Graphics Software and HYBRID Software – and its beauty lies in its simplicity: Fundamentals 2.0 makes it easy for the press operator to keep control of the workflow. Easy step and repeat and nesting via STEPZ with award-winning VDP composition from HYBRID Software makes it possible to estimate and plan single or multi-gang jobs and see how the output will appear when printed, helping to reduce errors and wasted media.

Consistent and predictable color for a wide range of design and creation workflows using industry-standard tools is achieved with Harlequin ColorPro ™  and there’s support for ICC profiles, including device ink and N-channel profiles too.

ScreenPro™, the award-winning multi-level screening engine, streams data directly to the print electronics at press speed, unlocking maximum productivity on variable data jobs to process ultra-high data rates with the reliability required to maximize press up time.

Find out more about Fundamentals here: www.globalgraphics.com/fundamentals

We’ll be on stand 9A15 – please stop by and say hello. If you’d like to book a time to chat, simply contact us: sales@globalgraphics.com. We look forward to seeing you.

Join us on stand 9A15 at Labelexpo2019

Looking for a simple way to print label and flexible packaging jobs? See us at Labelexpo Europe 2019

It’s that time of year again … we’re back from our summer vacations and are now preparing for Labelexpo Europe 2019.

And things have certainly moved on at a pace since we were last in Brussels: This year, on booth 9A15, we’ll be previewing a new version of Fundamentals™, our simple toolkit for building a digital front end. Fundamentals is a cooperation between Global Graphics Software and HYBRID Software and we have developed it so you can access the essential software components you need to create a DFE using a simple, modern web-based user interface.

The latest version, Fundamentals 2.0, has a host of new features that make it easy to print label and flexible packaging jobs in only a few steps and it reduces waste by making the best use of media – all this with accurate, consistent color throughout.

Fundamentals product manager, Tom Mooney says: “We are delighted to introduce some major changes to Fundamentals at Labelexpo, such as Hybrid’s STEPZ imposition and award-winning VDP composition engine, as well as significant technology evolutions with multiple parallel Harlequin RIPs for high-speed PDF processing. We have also introduced a new generation of ScreenPro™ that streams image data at the high press speeds demanded by the new models of digital presses.”

Earlier in the year, we visited Mark Andy Inc (find them on booths 4C45 and 8A60) and saw at first hand how Fundamentals has made a real impact on the Mark Andy ProWORX Digital Front End.

Watch our short film to get the full story:

http://bit.ly/Mark-Andy-Fundamentals

We’ll be on stand 9A15 – please stop by and say hello. If you’d like to book a time to chat, simply contact us: sales@globalgraphics.com. We look forward to seeing you.

www.globalgraphics.com/fundamentals

 

Join us on stand 9A15 at Labelexpo2019

Screening for the next-generation high-definition devices

In days gone by, almost every job was more or less 600 dpi in both directions. Now there is a drive to higher definition, with higher resolutions and smaller drop sizes.

So we’ve introduced a new feature in ScreenPro™ that allows the resolution of a job to be “upscaled” meaning that a RIP can still render at 600 dpi through an existing workflow and then ScreenPro can upscale the job to the printer resolution. The benefit is that you don’t need to change your existing workflow, can cut down on RIP time by RIPping at 600 dpi, but print on a 1200 dpi machine for increased definition.

There are various ways of achieving higher resolutions: use the new generation of print heads running at 1200 dpi, use multiple print bars, or use scanning head printers for multiple passes. Sometimes it really is increased resolution that is required and other times it is higher addressability and, for example with textile printing, sometimes you just need to be able to put down more ink in any given location.

Once manufacturers have achieved 1200 x 1200 dpi there are other problems to solve. There is four times as much data generated that needs to be passed through the workflow pipeline to the press compared to a 600 dpi data path. There are some applications where the higher addressability isn’t needed, and 600 dpi is ok, in this case you could run the press twice as fast and get twice the production if you ran it at 1200 x 600 dpi, or three times as fast at 1200 x 400 dpi.

To solve the problem of too much data slowing down processing times we have implemented resolution upscaling in the latest release of ScreenPro. The typical example is that we have an existing press and workflow to go with it at 600dpi. The RIP delivers data at this resolution. We then have a choice – to send it to the 600 dpi printer, in which case we screen as normal, or we send to the 1200 dpi machine.

In this simple case we use ScreenPro to double the number of dots it produces in both directions. For non-square resolutions we multiply in one direction only. Also for non-square resolutions we have to change the shape of the screens, a circular screen will be distorted by the non-square printer resolution so we have to correct for that up front.

What this means is that you can continue to RIP at 600 dpi and keep the same workflow right up to the last process of screening. You keep the same PC processor requirements, same network data transfer speeds. Only at the last stage use ScreenPro to upscale to your desired resolution.

This will be a really useful feature for many customers developing the next generation of high definition digital printers.

Hunkeler Innovationdays 2019
Join us at Hunkeler Innovationdays 2019 to learn more about the new features in ScreenPro.