what you need to know about computer to plate technology

8/2/2019 What You Need to Know About Computer to Plate Technology

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Imagine this situation: You’re with

your boss on her first visit to yournew folding carton supplier’splant. Everything’s going greatuntil you get to the printingdepartment, where your job justwent on press. That’s when shecomments: “Our logo on thispackaging should be red, not black.” Your stomach sinks.

What would your supplier say?

When Jan Steiner, President of aWest Coast folding cartonmanufacturer and IndependentCarton Group (ICG) member,faced this exact situation with amajor new customer, sheresponded immediately: “Noproblem. We’ll have new plateson the press by the end of theplant tour.”

Welcome to the world of computer-to-plate technology.

Before computer-to-plate (CTP)technology, producing platesinvolved the use of films. Theprocess started with digital orhard copy artwork. Packagingcompanies would first generatecolor separations (cyan, magenta,yellow and black versions of the

artwork), which would be used tomake films. Color separationswere often produced by anoutside firm, adding time andscheduling uncertainty. Oncefilms were prepared, light wasexposed through them to make animage on the photographicmaterial on the surface of theplates. The end result was plates

(one for each color) which were

used on the printing press totransfer ink to a paper substrate.

Computer-to-plate technology, incontrast, produces plates withoutthe interim step of making films.Digital artwork files, afterappropriate preparation, are sentdirectly to a digital platesetter,which produces plates directlyfrom the digital file. No filmsrequired.

CTP technology offers a numberof benefits in the production of folding carton and litho-laminate

packaging. However, the extentof these benefits will varydepending on several factors.

The most obvious benefit of CTPtechnology is faster turn-aroundtimes. Eliminating the need toproduce films can reduce the timeneeded to make plates from oneweek to a few days—or, inextreme cases, to as little as anhour.

“It used to

take seven toten days justto get proofsto customers,”says LisaHirsh,President of an East CoastICG memberthat produceslitho-laminatepackaging.“We used an outside firm toprepare color separations. If theywere busy, you could add anotherday or two to the process.”

Three years ago, her firm boughtone of the first Agfa large-formatCTP systems sold in North

America. “Itallowed us to bring the entireplate productionprocess in-house. The timeit takes to get a job on pressdropped to twoor three days,

includinggetting word back on proofsfrom thecustomer.” Thisis especially

beneficial for customers whomake frequent changes topackage graphics and thusfrequently require new plates.

This faster turnaround time alsoallows packaging buyers to catchmistakes earlier in the process.“When we get a disc withartwork from a customer, we getthem proofs the next day,”comments Ms. Hirsh. “Before we



had our CTP system, it wouldtake a week to get them proofs. If there was a problem, we had towait another week for newproofs.”

And in the rare instance when acustomer catches a mistake with a job that is on the press? “We canhave new plates on the line in anhour,” says Ms. Hirsh.

An additional benefit of CTPsystems is better image quality.Because plates are imageddirectly from digital files, CTPsystems do not result in thegeneration loss experienced withfilms. Combine this with superior

registration, and plates produced by CTP systems allow sharperdots than do film-producedplates. As a result, press-relateddot gains are reduced, allowingpress operators to lay downgreater ink densities and run jobswith finer line screens.

“The quality improvement issignificant, especially whenyou’re printing faces, food items,or other high quality graphics,”

notes Jan Steiner.

CTP systems are also supposed toreduce costs, although results can be mixed. They eliminateexpenditures on consumablessuch as films and the chemicalsrequired to produce them. Theyalso require much greaterautomation of the printingworkflow, thus reducing laborcosts and human error. “Since weinstalled our CTP system, we’ve

virtually eliminated plateremakes,” comments ErikPeterson, Operations Manager atan ICG company that specializesin packaging for industries suchas pharmaceuticals and biotech.This has resulted in significantcost savings.

But significant up-front capitalcosts and on-going maintenanceand upgrade expenses can offsetthese savings. In addition, thecost savings associated with fastermake-ready times can be elusive.

“We haven’t seen a hugedifference in make-ready times,”says Lisa Hirsh. “We werealready good at getting our jobsup-to-speed; our CTP system hashelped us more in other ways.”

So although CTP systems offermany benefits, cost savings isn’tnecessarily the biggest one.

Proofing has been one of the biggest challenges associated withCTP systems. Traditional film- based systems provide theopportunity to generate proofsmade from the same films used toproduce plates. Therefore,packaging buyers know whatthey see on a proof is what theywill get from the printing press.

The absence of films in CTPsystems makes generating anaccurate proof more challenging.Until recently, digital proofsassociated with CTP systemscould not match colors with 100%reliability. But that’s changing.

“We found the quality of thelatest generation of inkjet printers just incredible,” says ErikPeterson. Incorporatingtechnology developed for digital

photography, today’s top-endinkjet proofing systems are able toaccurately reproduce not justprocess but also spot colors.Some inkjet printers can evengenerate halftone dots, althoughwith today’s technology dots arenot necessary to match colors.

To ensure accurate representationof colors on proofs, Mr. Peterson’sfirm profiles, or fingerprints, theirprinting presses using profilingsoftware. This data allows themto match house densities to the

inkjet proofer. The same softwarecan be used to calibrate inkjetproofers at locations of thepackaging buyer. This allows foraccurate remote proofing, inwhich an electronic file is sentdirectly to the buyer’s printer.

But proofing for color can still bea challenge for many packagingfirms with CTP systems. Inkjetproofing systems made before2004 will provide excellent proofs

for content, register, fit, trappingand other areas related to the finalprint. But if exact color matchingis essential, firms without thelatest proofing systems will needto provide ink swatches for spotcolors and use an outside supplierto produce a dot proof for processcolors.

And even the latest generation of inkjet proofers cannot print on theactual packaging substrate. If a

color proof on the substrate isrequired, even firms with themost recent inkjet proofers willneed to provide a press sample ordot proof from an outside vendor.

The bottom line is, CTP systemsallow packaging suppliers to offera number of benefits for buyers of

folding carton, litho-laminate,and other types of packaging.But CTP technology is not alwaysa panacea and not necessarilyimportant for all packaging buyers. There are a number of things to keep in mind.



First, you should decide if it isimportant, for your specificpackaging needs, to have asupplier with a CTP system. Youare most likely to benefit from asupplier with CTP technology if:

• You have frequent changes toyour graphics, requiringfrequent plate changes;

• Premium image quality isessential; or

• Turnaround time and speed-to-market are important to your business.

On the other hand, if you makelong print runs with existing filmsand rarely have copy changes, it

is probably most cost-effective tokeep your business in a film- based platemaking environment.

Second, talk to your packagingsupplier about the kind of proofing system it uses. Askwhether they fingerprint theirpresses to match ink densities totheir proofing system. If you areconcerned about the coloraccuracies of proofs, ask them toprovide comparisons of digital

proofs to press samples. This willhelp your organization becomecomfortable with digital proofing.If you are still concerned aboutexact proofs of match colors, askfor an ink swatch on the type of substrate your packaging isprinted on.

Finally, ask your supplier orpotential supplier if they haveadopted a fully digital workflow.The more the printing

workflow—from prepressthrough to the printing lines—isautomated, the more yoursupplier will reap the benefits of CTP-related efficiencies. It willalso allow for more seamlesscommunication between yourorganization and theirs.

Ultimately, it’s important toremember that just because asupplier has a CTP system thatseems to meet your needsperfectly, it doesn’t mean thatthey will meet your needs in

other ways. A mammothpackaging supplier with aninflexible organization will not beable to turn around new plates inan hour whether they have a CTPsystem or not. So as you assess asupplier’s CTP capabilities, don’tforget that other considerationslike responsiveness, flexibility,and overall cost structure willalways be paramount.

Further information on CTPsystems is available from thefollowing sources:

• http://graphics.agfa.com/pdf/white_papers/wp_ctpreview_1_2004-02-25_en.pdf

• http://www.dotprint.com/technology/prepress/ctp/

• www.gain.net

You are also welcome to contactthe Independent Carton Group at(203) 270-7578.

Agfa, the approved supplier forCTP systems and plates for ICGmembers, provided technicalinformation and other assistance inthe preparation of this white paper.For more information about CTP

systems, contact Agfa or any ICGmember.

what you need to know about computer to plate technology

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