Print Buying Direct

Offset Lithography – Printing to you and me! – Part 6 – 20th April 2009

Experienced single colour litho machine minders from the 70s will also remember those stressful days when it was paramount to get all four process colours down in one day to avoid dreaded paper stretch problems, a common happening in litho printing due to the use of water. These jobs were often produced on a press that would run at a maximum 6000 sheets an hour to maintain good register. In the late 70s, two hour long press make readies were commonplace, without densitometers for a colour guide, or automated plate skewing and using manual ink duct settings. All that was needed in those days was study spanner, a set of progressives and a good eye for colour guidance, a fair wind and a lot of luck if you were to get all four sides of a 10,000 run brochure off in one day.

To be continued…

See parts one, two, three, four and five of this blog – Offset Lithography - Printing to you and me!

See our recent Design of the Times Blog Part 1, Part 2, Part 3, Part 4 and Part 5

Print Buying Direct is the online facility for buying print of The Printing House Ltd of Crewe, Cheshire, UK

The Printing House are specialists and experts in Prospectus of all kinds – see our dedicated prospectus Website www.schoolprospectus.info

Don’t forget to see our new offer – Budget Black and white leafets – 10,000 Leaflets designed, printed and delivered for only £199

Offset Lithography – Printing to you and me! – Part 1 – 15th April 2009

Offset litho is by far the most popular form of printing accounting for something like 40% of all printed output worldwide. In fact so popular is it, that you can even view 259 separate videos of litho presses in action on YouTube!

The process itself has basically remained the same since the 1700’s when it was inverted, but no end of technology has been applied around the basic principle of oily inks repelling water. What has changed is the speed and quality which are now a given, and all manufacturers of offset presses pride themselves in quick make readies and high running speeds, something the original inventors of the process would be now deeply impressed with. What has also dramatically changed is getting the image on to the press from finished artwork, which is probably the most remarkable change to happen to the process in its 300 year history.

To be continued…

See our recent Design of the Times Blog Part 1, Part 2, Part 3, Part 4 and Part 5

Print Buying Direct is the online facility for buying print of The Printing House Ltd of Crewe, Cheshire, UK

The Printing House are specialists and experts in Prospectus of all kinds – see our dedicated prospectus Website www.schoolprospectus.info

20th January 2009

When looking at the folders the first thing you need to consider is which of the three options- knife, buckle and combination will suit your needs?

The buckle folder is the most common choice. It uses a set of guides and plates with a backstop to buckle the paper and create the fold. The document enters through a set of rollers and into a plate where the paper strikes a backstop; it buckles and is forced downward and into a set of nip rollers. The nip rollers grab the sheets at the buckle and pull it through, pressing a fold into the sheet. If several folds are required, then the sheet is sent into another plate and the process is repeated. The fold or buckle location is adjustable allowing for different folds to be created. A knife folder uses a blunt steel blade to push the sheet at the right point to create the fold in the material. Its accuracy makes it ideal for booklet work.

Finally the combination folder- using both buckle and knife technology- is faster and provides close registration. It is suited to large quantities and more complex folding jobs. With the issue of toner cracking on digitally printed work still a key consideration the choice of folders can be more complicated. On the whole, a suction fed system rather than friction fed- usually used for litho printed stock- will offer greater protection to the surface. And creasers have been developed specifically for the digital print.

How much automation does your guillotine have? Is there a touchscreen console? An air table? A quick and easy-to change knife? If ‘none’ and ‘no’ are the main answers to these questions the chances are you are one of the majority of printers that only upgrade equipment when it is absolutely necessary.

At some point during the lifecycle of most pieces of print they will go through a guillotine or a trimmer, so getting a high- quality finish is vital. Although often overlooked for investment, this piece of kit, when upgraded, can transform the bindery. This is especially the case now as the demand for automation has increased and the cost of adding features to smaller machines has reduced. The result is more affordable highly-automated kit.

But what should a new guillotine feature? To get the best out of the printed sheet it should have programmatic capability to store jobs and reduce wastages resulting from errors in set-up, ease of use to enable fast changeovers between jobs and variable clamp pressure to hold a variety of stock and enable a clear cut; the latter being important when cutting digital stock.

For more information on printing, trimming, and print finishing in general please don’t hesitate to contact us at The Printing House (Print Buying Direct)

While many of the other stages in the bindery have been an essential element of post press, lamination is a relative newcomer. Previously restricted to trade finishers because of the prohibitive cost of the machines and the skills required to ensure top-quality results, the popularity of digital print has pushed this process into the spotlight.

With the increase in demand for short run, fast turnaround products printers are being required to work faster and smarter. As a result lamination is increasingly being used to protect the final product and give it a high-quality finish. But because sending this out could have ramifications on turnaround times and create unacceptable waiting times, printers started to look at the issues surrounding bringing this service in-house. At the same time, manufacturers were making technology advances that meant easy-to-use and cheaper machines.

A fully automatic laminator should cope with both lithographic and digital output for example and consideration should be given as to how easily a feeder could be added to a hand fed laminator at a later date should the printer’s volumes increase. It should be built for longevity of use and be backed by a comprehensive service organisation.

This is true for B1 and B2 printers and now includes B3 and digital printers, too. Despite increasingly tighter margins, printers are realising the added value a laminator can bring to their businesses. The time and cost associated with outsourcing means that printers are now keen to reap the benefits of providing all their offering under one roof, as a means of creating another profit centre. With modern technology making the lamination process so simple, the need for highly skilled operators has disappeared. Having a laminator in-house means that printers have greater control over the job at hand, there’s faster turnaround and as a result many printers are actually winning new business.

To ensure successful lamination the minimum diameter for a nip roller should be 10 inches so it provides a decent amount of nip pressure, together with a good water heating system.

For more information on printing, Gloss Lamination, Matt Lamination and print finishing in general please don’t hesitate to contact us at The Printing House (Print Buying Direct)

Ever since we started to handle colour images on mainstream computers, colour management of some sort has been a necessary evil. Although one would think it ought to be getting easier by now, there is still room for improvement. The rising number of digital devices in the workflow means that we are dealing with devices such as digital cameras, scanners and monitors that work with emitted light, describing colours in RGB (red, green and blue), but printing them by manipulating reflected light using cyan, magenta and yellow inks. To these primary colours we add black, the key which together with CMY creates the illusion of the other colours we can see.

ICC

Modern colour management largely depends on technologies developed by the ICC (International Colour Consortium), which bridge the worlds of RGB and CMYK using a larger colour space to describe colours, in combination with device profiles. Every device, whatever it is, represents colours uniquely. Different monitor brands and models have slightly different colour fitters and in practice this means that a given colour expressed in RGB values, creates slightly different colours. Black described in RGB has values of zero for each channel because no light is emitted for red, green or blue filtered phosphor guns. Conversely white is created with full signal strength on all channels, encoded as 255, 255, 255 when using 8 bit data per channel for 256 level of grey per colour channel.

Calibration and characterisation with ICC profiles

In order ensure that two different monitors display colours in as similar was way as possible, they need first to be calibrated and then characterised using a colorimeter or spectrophotometer. The second stage, characterisation, refers to the creation of a unique ICC profile for an individual monitor, describing the colours it produces for different RGB-values. The ICC profile comprises a table of RGB values and the colours expressed as a corresponding series of CIElab values. CIElab is the universal colour language, used not only within the graphic arts, but in the most situations where exact colours need to be described.

Calibrating monitors

When calibrating a monitor it’s important to set brightness and white point. Images should then look the same when displayed on a monitor, as when the reproduced image is viewed in a viewing booth. In print publishing, the reference white point is 5000 K (Kelvin), a warm white light which is a compromise between even warmer looking indoor light from bulbs or fluorescent tubes, and slightly colder (bluish) outdoor daylight. The white point of average outdoor daylight is around 6500 K. this is often the reference white in photography, but not in print. The viewing booth at an offset press is set to 5000 K, so if we want to preview an image as it will appear in print, this is the white point we need to use. The brightness level also needs to be matched and in a viewing booth this is between 1500-2500 lux, which is quite an intense light. For a monitor this is equivalent to a brightness setting of around 120 Candela per square meter (cd/m2). Obviously there are challenges when trying to preview images on a monitor, and match the appearance of the printed version, but it can be done. Perhaps not on any cheap monitor, but at least on high end CRT and LCD monitor rs.

Calibrating printers and presses

Colour printers and printing presses are slightly more cumbersome to calibrate than monitors or scanners. The first step is to linearise the printer or printing press. This is basically to make sure that for example 40% cyan really comes out as 40% when printed on paper. On a colour printer this is fairly straightforward to accomplish, assuming you have a function for linearisation in the RIP software.

For conventional printing presses, matters are slightly more complicated, since we have to factor in different dot gain levels for different types of paper stock. Another thing to bear in mind is the ink that will be used. Even thought the ink manufacturer should comply with the ISO standard for ink, in reality individual batches may need to be checked with a spectrophotometer. When correct dot gain values are compensated for in the platesetter, a reference test chart can be printed, and the ICC profile for this press and paper calculated.

Once all devices in the digital imaging process are calibrated and characterised and ICC profiles have been created, colours can be converted back and forth depending on the need and the publishing scenario. This could mean creating a softproof on the monitor, or hardcopy proof on a colour printer. Using this methodology also simplifies the automatic conversions from one print method to another using the advanced functions in modern RIP systems.

When to convert RGB to CMYK

The decision to use a particular paper stock or printing press is often made very late, so is it wise not to perform colour conversions until in the very last minute, since paper and print obviously influence colour. The unconstrained workflow is generally referred to as an RGB workflow. Images are placed as RGB in layout software, and PDF files are created with an assumed output profile embedded, but the actual images remain described using RGB values. By applying the correct output profile in the RIP at the output stage, we minimise the number of colour conversions in the workflow, and ensure that the correct ICC profile is used, taking into account the paper stock and print method used. The layout software, be it InDesign or Xpress, can preview the images even if they are in RGB, by temporarily applying a specific ICC output profile. Adobe Acrobat can also do this for previewing PDF files on screen prior to output.

Spectrophotometer

If properly controlled, a modern, ICC colour managed workflow offers predictability and good image quality, as well as workflow flexibility and tools for production automation. The key is to have the right measuring tools in order to both calibrate and characterise the devices involved. In order to measure total ink density and dot gain you can use a densitometer, but a modern spectrophotometer has this function and does more besides. To calibrate a monitor you need at least a colorimeter, or better, a spectrophotometer and in order to check CTP plates, and linearise the platesetter, you need a spotmeter, because a densitometer can’t accurately read plates.

All modern press control systems use spectrophotometers at the press in order to check that prints really do match the required quality level. The shorthand used to describe colour accuracy is Delta E (∆E), a value that indicates the colour difference from a certain target, expressed in CIElab, and what you actually achieve. A value of ∆E 1 is impossible for humans to differentiate, so we cannot perceive any colour difference and value of ∆E 2 means that the colour difference is just barely noticeable. Depending on the paper stock used the printing method, for most printers an average ∆E value of 4 is considered an acceptable match for quality offset production. For good quality control throughout the print run, the ∆E variation should be monitored and the data saved for later analysis

No-one should claim that colour management is easy to implement, nor to maintain. However, with proper training and using the correct hardware and software it can be done successfully.

For more information on colour management or printing in general please don’t hesitate to contact us at The Printing House (Print Buying Direct)

Designing For Print

Information supplied courtesy of Print Buying Direct at The Printing House Ltd

We get asked all the time about how to design for print. This blog focuses digital print as we find many designers haven’t ever been advised of the advantages or limitations of digital print. Obviously many things are still relevant to litho printing (this still remains our core business) so whatever kind of print you design for hopefully you can draw something useful from the information below.

TEXT CONSIDERATIONS
GENERAL

• Include all fonts in both page layout and vector graphics files.
• Supported font types include PostScript Type 1, 3, OpenType, TrueType, Multiple Master
• When possible, select fonts from the Font menu and use caution when working with stylized fonts from the Style menu.
• Preserve text as a font; do not rasterize text in the application.

TYPE COLOR

• Create solid black text with 100% K only for the most dense black.
• As with any digital or offset printing system, saturated text presents the best appearance. When a tint is used, the halftone screen may be visible on the edge and cause a jagged appearance. Text containing at least one ink of 100% C or M or K presents the best appearance with solid, rich colors
• RGB solid text, such as 100% red, may reproduce as a tint. Define solid color text in CMYK if possible.

TYPE SIZE

• For positive solid text use a minimum of 4 point and 6 point for reverse.
• For positive tinted text use a minimum of 6 point and 8 point for reverse.
• With smaller text, sans serif fonts are recommended.

GRAPHICS CONSIDERATIONS
COLOR IN GRAPHICS

• Colors for fine rules or small graphics, such as bullets and icons, print best when at least one color separation (other than yellow) is set to a solid or near solid color (e.g., 90-100%).

SPOT COLORS (PANTONE)

• Select PANTONE colors by choosing them from the PANTONE color library.
• Do not change the name of PANTONE colors (e.g., PANTONE 106C to Sunshine Yellow or to PANTONE 106C copy).
• When PANTONE colors are desired, it’s always safest to ask us how the colours you want are best printed.
• Be sure to specify the color as a [Spot] color. This will allow the digital press to provide the best spot color accuracy within the limitations of the printer. (THIS IS THE EXACT OPPOSITE OF DESIGNING FOR OFFSET/LITHO PRINTING – PLEASE ASK IF UNSURE)

GREYS

• Grey text, graphics, and gradients will be best produced if they are created with K only in a CMYK working space.
• Grey balance is dependant upon selections made at the printer. If you are creating grey colors with RGB or CMYK combinations, consult us for the appropriate values needed to achieve good neutrals.

BLACK

• When printing black on uncoated substrates, add a small amount of C, M or Y to improve uniformity and minimize paper texture.

TINT UNIFORMITY
Digital printing systems, in general, may show slight variations in color within large areas of mid-density tints. Color variation may be emphasized with coated stock due to smoothness of the paper.

• Design with smaller areas when using tints and/or design with colors that are less than 40% or greater than 70% in value.
• Sensitivity to color variations may be reduced by introducing a texture or by adding text or graphic objects.

GRAPHIC EDGES

• Edges of tinted areas may also have a jagged appearance, dependent on line frequency and the angle of the halftone screen with respect to the angle of the edge. When selecting the color for fine rules or elements, better results will be achieved by choosing saturated colors or setting at least one separation (other than yellow) to 100%.

GRADIENTS
The best produced gradients will be produced when using vector gradient tools in programs such as Illustrator that take advantage of PostScript Language Level 3 and PDF 1.3 Smooth shading operations.

Following are suggestions for achieving the smoothest gradients:

• To ensure enough gray levels, gradients length should be greater than 2cm.
• Use a color change of 100% for at least one colour separation for gradients less than 2 cm long and a change of 50% for gradients less than 4 cm long.
• Adding Noise or a Gaussian blur can improve gradients in Photoshop.
• Saturated colors generally produce the smoothest blends.
• Avoid creating gradients that blend from a very dark color (e.g., navy blue) to white. They have a tendency to have more banding.
• For gradients blending to white, set the same color to 0%. Do not use white. Example: first color PANTONE 032C: 100%, second color PANTONE 032C: 0%.

I hope you’ve found this useful. More useful hints to follow in the next few days.

We start off our day by checking the 4 printing presses we have, Litho B2, SRA2 & SRA3 sizes and digital SRA3, which work was completed on the late shift, we print till 10.00pm Monday –Thursday and work finished on the early shift, presses start running at 6.00am Monday – Friday.

We then have to ask plate making where they are up to with the plating of print jobs. Generally they are ahead of the game and usually chase production for more work to be plated. This generally relies on which jobs have had artwork signed off by the customer. Each time a job is booked in and we have had to design it or with the case of print ready artwork, we have to rip it through, we send a proof across to the customer for checking, usually a pdf or if the customer requires a colour match it would be a Contract Proof (Colour Accurate).

The production office runs by a ‘Tee-card System’ which means by glancing at the production board, we can instantly see where each job is currently up to and can very quickly assess customers delivery dates when they ring up to see how quickly print jobs can be received.

The production office will mainly generate the delivery dates for each job, but in the case of the customer requesting delivery dates, we adhere to this and will make sure paper is ordered in plenty of time, so when the job signs off we can issue it to a press straight away for printing.

Meetings are held daily with Production, Studio Manager and the Works Manager so we can discuss together the order of sign offs, print and deliveries.

Lisa & Steve – The Production Office – The Printing House Ltd (Print Buying Direct)

From the perspective of James (Jacko) Jackson – Pre-Press Apprentice

Here at The Printing House (Print Buying Direct) we have a very skilled work force in all the areas needed to cover day to day activities. Once we take your order – either online, by email, fax, FTP, or phone, the job will be sent straight down to the pre-press (before printing) work area. There, one of our team will prepare the artwork for print, whether it is folders, flyers or business stationery for Litho printing or Digital Printing. All work is prepared in the same way by checking and ripping the job through our market leading print workflow software ‘Heidelberg Prinect Printready, this software checks to make sure your job will print correctly.

If you ordered online then you need do no more, if you have ordered via our office, a proof (PDF or Contract) is then sent to you for final sign off. Once sign off is achieved, the job is ready to print and passes to our Printing Department.

James

With digital print, personalising each copy (Variable Data Printing) is easy and cost effective as there are no printing plates used in the process unlike litho. Small quantity jobs are fast and inexpensive. Digital printing is high quality and is suitable for printing and/or personalising newsletters, direct mail items such as leaflets or postcards, business cards and any application that combines variable images combined with unique personalised information.
Litho printing (the full name is Offset Lithography) offers a slightly more superior print quality (although digital is very good nowadays), especially where colour matching is important. Litho is best suited for long run, higher quantity print jobs where the highest quality is required.
Where the high quality of litho is required combined but with the flexibility of digital variable data, call one of our print professionals on 0870 950 8444 for an informal chat and a quotation. Or fill in our online form.
Here at The Printing House we are probably the most experienced printer in the not only in Cheshire but in the North West dealing with litho and digital information. We are also one of a very small number of printing companies capable of Variable Data Printing and have the full XM Pie U Direct Professional suite of software.

Not sure of some of the technical printing terms?.
You’re not alone, the printing industry is littered with technical terminology and jargon, but it needn’t be daunting or complicated, call one of our print professionals here at The Printing House (Print Buying Direct) on 0870 950 8444 and we’ll guide you through some of the issues you may be unsure of. Whether it be a single sided flyer, pamphlet or colour brochure, call now for some sound impartial advice.