Our expansion over the past 30 years also necessitated a constant evaluation of client expectations. Our quest to meet and exceed these expectations led us to become G7 master-certified in color calibration. We are currently one of only six printers in the entire state of Virginia, and the only printer in Hampton Roads, to carry this distinction. In addition to the rigorous standards of the G7 certification process, we have also implemented FM (Stochastic) screening within our offset printing process. Unlike traditional AM screening, Stochastic screening allows us to produce sharper images across a wider color gamut while eliminating moiré pattern and jagged edges. While quality is a top priority at Professional Printing, our processes take into serious consideration our responsibility to the environment. We are proud to be FSC-certified and routinely recycle our paper waste, inks and printing plates in order to reduce our carbon footprint.

We are excited about the next phase of our expansion, as we forge ahead with a significant upgrade to our online capabilities. In the coming months, we will be making it easier for you to obtain an estimate, place orders online, check your account history and track your job throughout the production process.

I would like to close by thanking you for your past and present support, and I encourage you to share your ideas on how Professional Printing Center can better serve your business in the future. It is through your feedback that we refine our processes and sculpt our services to ensure doing business with us is an experience that exceeds your expectations. Please feel free to leave a comment or give me a call to discuss how we can improve our service to you.

Best Regards,

Brian Ward
President, COO

What is AM Screening?

The idea of halftone screening (also called AM screening) was first conceived in 1850 by William Fox Talbot. He suggested using photographic screens or veils to produce photographic images in the intaglio printing process.

By 1881, the first successful commercial halftone process was patented by Frederic Ives of Philadelphia. Additional improvements followed in the decades to come, but the technique has largely remained the same since first conceived in 1850. This technique is still widely used by today’s printers, but there are many disadvantages which lead to a loss in quality of photographic images.

AM screening (Amplitude Modulation,) utilizes a fixed linear dot pattern with various sized dots to emulate the tonal range in photographic images and color builds. Standard AM line screens vary in resolution depending on the reproduction process and equipment quality. In commercial offset printing, these line screens are typically recognized as 100, 133, 150, 175, and 200. These numbers represent the number of dots per linear inch. The larger the dot the darker the image area, and the smaller the dot the lighter the image area.

Color images utilize a separate AM screen for each of the primary process colors, Cyan, Magenta, Yellow and Black, or CMYK, much like a computer screen utilizes the primary spectrum of light, Red, Green, and Blue, or RGB. These screens are printed on top of one another, which gives the range of color we see on paper. The color we see in a printed image is more of an illusion, because our eyes can only discern so much detail at a given distance. If we used a high powered magnifying glass to enlarge an area of a printed photograph the image would become unrecognizable.

Although the AM screening method has proven to be adequate for the past 100 plus years, it does have unavoidable technical limitations. In printing, we are limited to a minimum dot size for ink to adhere and transfer back to the sheet of paper we’re printing on. We’re also limited at the other end of the tonal spectrum, because we can only go so large with the dot before a printed area becomes a solid. This results is an inherent flaw in the process called posterization, and we have to adjust the photographic image before printing to reduce the problems it creates on press. When we make these adjustments, we are actually degrading the quality of the original photograph slightly overall, so we lose detail, color, and contrast. It’s a necessary step in the AM screening process, and much of this is automated with todays technology.

This technical correction process shouldn’t be confused with photo correction due to normal color shifts from the RGB model to CMYK model, or poor photography. These adjustments can be more of an art, than science, because every press prints a little differently, and printing conditions change for a multitude of reasons on every job. How well your images look are entirely dependent on company management, quality control processes (or lack of), and the expertise of their prepress department. The most serious offense would be the lack of quality control, specifically where color calibration is concerned. If a printer doesn’t have a regular procedure in place to assure calibration, it is nearly impossible to be reasonably accurate, or consistent in color reproduction.

The sizes of the dot in AM screening is also an inherent limitation to the visual resolution of a printed image. As we said earlier, AM screening uses a fixed dot pattern, and the tonal range is achieved by amplifying the size of the dot within that fixed pattern. Printing presses can only print so small of a dot, and they have to have a printing range between the smallest possible dot and largest possible dot to achieve a tonal range. So the peak resolution in an AM Screen is set by the largest or coarsest dot, not the smallest one. For a 175 line screen, the smallest possible dot ends up being approximately 10 microns, and the largest dot ends up being approximately 200 microns.

One of the most glaring problems in AM screening is a visible pattern in the image, which is another technical limitation of the process. Sometimes this pattern conflicts with the actual subject matter in the photo itself, and amplifies the negative visual effects of the process. The human mind recognizes patterns fairly easily, so anytime we incorporate a fixed pattern into a process we naturally detect that pattern. As we said earlier, color images are built on a series of screens printed over top of one another, and these screens are turned at specific angles to reduce the inherent negative effects. The flaws are still there though, like moire patterns, and rosette patterns, but we try our best to reduce the obviousness of the technical limitation. This is one big reason companies are insisting on FM screening, especially in the apparel industry where subject matter is all about patterns. Needless to say, there can be a plethora of adverse pattern conflicts with the AM screening method.

What is FM Screening?

Although it is widely recognized that Stochastic FM (Frequency Modulation) screening was first conceived in 1965 by Karl Scheuter, at the Technical University of Darmstadt in West Germany, there is also a rich history of contributors that helped make this technology possible.

The core technology involves high level computational algorithms, which can be traced back to as early as the late 1800′s, by a man named Ladislaus Bortkiewicz. We can also consider Floyd-Steinberg dithering, developed in 1976, or a technical paper “Frequency Modulated Picture Recording with Random Pixel Distribution” published by Scheuter and Gerhard Fischer in 1984, then subsequently publicized by GATF in 1985. However, most of the core mathematics appear to have their roots in the “Monte Carlo method”.

The term “Monte Carlo method” was coined at Los Alamos National Laboratory in the 1940′s, while physicists were working on the US nuclear weapons program, or Manhattan Project. This method used complex computational algorithms that rely on repeated random samplings for their results.

One thing does become clear; the fundamental mathematical understanding of the FM screening process proceeded the physical technology by a solid 50 plus years. It wasn’t until the development of affordable compact laser diodes, and cheap high speed microprocessors, that we were able to apply these complex algorithms directly to printing plates commercially in the late 80′s and early 90′s. This technology is referred to as CTP (Computer-To-Plate) in the printing industry. This breakthrough in technology virtually eliminated an entire process in the manufacturing of printed material.

Even though most, if not all of these CTP devices are capable of printing an FM dot on a printing plate, many printers have been apprehensive, and still opt for AM methods. The reason is fairly straightforward, because we have to have our shops in order, and expand our learning to be able to apply the new technology. Even printing the dots correctly and consistently on the plate becomes a challenge, because it’s a very small image, so regular calibration and cleanliness is an essential part of the process. A printer has to change the way they operate, and educate themselves, because printing an FM screen is an unforgiving process on press with very little margin of error. Once a printer makes the transition to FM screening though, it becomes more efficient, and proofs tend to be easier to match with less unforeseen screening surprises on press as in the traditional AM screening method. The end result in the finished product is also a substantial improvement over the traditional AM method, so customers benefit greatly. Ultimately, printing companies that continue to drag their feet will become relics, and go the way of the VHS

Although FM screening utilizes the same concept of CMYK printing as in AM screening, any other similarities end there. FM screening is not a fad technology, it’s an upgrade technology for conventional offset printing. And while this new technology isn’t without challenges, overall end results yield significant improvements over the old method. Most casual print buyers probably won’t understand the intrinsic differences between the two methods, but they will understand, “this print looks much better than that print.”

The FM screening process utilizes very small micro-dots, about 10-20 microns, which are placed randomly, but the frequency of those micro-dots increases or decreases depending on the tone of the image area. The lighter the area the fewer random dots, and the darker the area the more random dots.

The difference in resolution between FM and AM screening is difficult to quantify, because the processes are very different. As we discussed earlier, AM screens use variable sized dots within a fixed grid resolution. FM screens use very small static dots (some versions of FM vary the dot size slightly) that are randomly placed throughout the imaging process. If we consider a 20 micron FM screen for instance, we can pack about 1270 dots per linear inch, where as an AM screen will always be limited in resolution to the screen ruling number, like 175 dots per linear inch.

Screen resolution is paramount in holding fine line detail within images. The gain in detail in the FM screening process is enormous compared to traditional AM screening. This is because the dot we are using in the FM process is very small in comparison to the screen resolution in the AM process. For instance, if we took a .5pt rule with a 20% black screen, an FM process will randomly dot that entire line with various points of black to achieve the proper density. AM screening can’t process the entire line, because it’s limited to a fixed grid of dots. So it can only adjust the dots along the fixed grid with the proper density. If that line falls between the grid, or points on the grid, nothing prints in that area. The result is a dotted line with possible breaks within the line. Not to mention potential pattern conflicts with the linear elements. This benefit isn’t limited to picture elements though, because it can greatly improve color build elements of type and vectored graphics as well. The end result is sharper photographic images with better detail and better color graphic elements, like type, vector images, and rule lines.

These differences in resolution and random dot placement plays a key role in achieving a higher color gamut in the FM screening process. This is because FM screening is altering the frequency in the occurrence of the printed dots, and that frequency can be adjusted from 0% to 100% in any given area. AM screening can’t achieve the same results, because the fixed grid can force the size of the printed dots on plate beyond what is physically possible on press. Essentially, a 175 line AM screen always has a resolution of 175 dots per linear inch. If the smallest dot we can print is 10 microns within the AM screens tonal range, than anything beyond 10 microns doesn’t print. Any color builds needing a smaller dot with the AM method become impossible to reproduce, because the tonal range in that process always falls between the smallest and largest physical dot possible within a fixed grid of resolution. The FM process has no set grid resolution to worry about, so it can print a 10 micron dot at any spacing it needs to achieve a particular hue. This becomes particularly important in lighter shades of color, especially in the pastel range.

Random dot placement is the most advantageous aspect of FM screening. By randomly placing very small micro-dots at various spacings, we eliminate all the adverse effects of linear pattern interference caused by the AM screening process. We no longer have screen angles to contend with, which generates undesirable effects, like moire pattern, and rosette patterns. We also don’t have to concern ourselves with conflicts in the subject matter of the actual photo, so no surprises on press.

And because we have much tighter control on the dot structure, FM screening also uses less ink. We simply don’t need to run as much ink density to achieve the same visual appearance as in AM screening. This adds up to savings both financially, and environmentally. FM screening is a greener technology, and it saves money.

To put all of this into perspective, a 1”x 1” CMYK image built with a 175 line AM screen, can only manipulate 122,500 points (175x175x4) of information to reproduce an image. A 20 micron FM screen on the other hand, utilizes a full 6,451,600 points (1270 x1270x4) of information to create that same image, within that same 1”x1” area.

Printing is an illusion of scale, because the human eye can only detect so much detail at a given distance. The more information we can pack into a printed image, the more natural that image is perceived by the human eye. Conventional AM screening will always be limited by the resolution of the line screen, where FM screening is only limited by the size of the printable dot. Both processes have technical limitations, but FM screening takes the printed image to the next level of fidelity. FM screening also incorporates randomness, exactly as nature does in the real world. Imagine how boring life would be if all leaves were the same shade of green…
The closer we come to emulating nature, the closer you are to “The Nature of Color.”

Stochastic or FM screening utilizes a micro-dot that is randomly placed throughout the image. As a result, FM screening produces a much higher resolution than the AM screening methods. For comparison, a typical 20 micron FM screen would be roughly similar to a 365 line AM screen, which is more than twice the screen resolution of a standard 175 line AM screen used on most offset presses.

Conventional or AM screening utilizes a variable dot size along a fixed grid. This dot ranges in size from about 10 or 20 microns, to over 200 microns. What’s important to understand is that physical resolution will always be limited by that fixed grid, no matter how small the dot. The resulting technical limitations within this process yields potential flaws in picture quality, like moire patterns, rosette patterns, color loss, and loss of detail.

Some of the clear advantages to stochastic printing are:

• Improved detail and definition
• Reversed text prints cleaner
• Improved highlight and shadow detail
• Wider color gamut

To put this into perspective, AM screening compared to FM screening is like comparing a VHS Tape to a Blu-Ray Disc. Sure, a VHS tape works, but would you buy one today? The printing industry has been very slow to adopt this technology on offset; not because it isn’t better, because it’s a difficult transition internally. The switch requires calibrations, upgrades, and a willingness to learn and keep up with the best technologies available. Eventually AM screening will go the way of the VHS, but until then you can count on us to provide your company with the very best offset technologies of today, so you’ll be here tomorrow.

Ask your printer what line screen their offset presses use. If they give you a number like 175, they aren’t using FM screening.

For a more comprehensive explanation, CLICK HERE!

G7® is a Method defined by the Print Properties and Colorimetrics Working Group of IDEAlliance.  Initially G7 was developed by the IDEAlliance GRACoL Working Group.  But as adoption of G7 grew, it became clear that the application of this method that enables printers to reproduce a similar visual appearance across printing types and substrates should be addressed by a group with reach beyond the focus on sheetfed offset printing that is unique to the GRACoL working group.  Today, through the PPC Working Group, experts from across the spectrum of printing disciplines contribute to this important IDEAlliance Methodology.

G7® specifies the components of an image that define a similar “visual appearance” to the human eye.

To do this, the G7 Method:

• Defines a colorimetric definition for gray balance.
• Specifies gray balance in the mid-tones, image weight and image contrast from the highlights to the shadows which are the factors that determine likeness of the visual appearance of an image.

Professional Printing Center is a green, FSC certified full service commercial printing company featuring the finest, most advanced digital pre-press and printing technology available.

For all your professional printing and mailing needs, including full-color business cards, flyers, brochures, newsletters, postcards, catalogs, stationery, door hangers, menus, pocket folders, and much more, we deliver. Our 24,000-square-foot printing facility is home to the latest in printing and mailing technology. Whether you’re working on a Mac or PC, Microsoft Office or Adobe CS, we process thousands of files every year from multiple platforms and software applications. We can also handle all of your direct mail needs, with our robust in-house direct mail operation.

We can deliver high quality on-demand full-color printing with our HP Indigo 7000. Unlike a typical toner-based digital machine, HP Indigo uses an electrostatic liquid oil process which offers superior offset-like quality, at on-demand pricing and service. It’s variable data capable as well, and we can quickly produce 24 two-sided color prints, or a 24-page full-color calendar without skipping a beat. The quality and versatility of the HP Indigo is unparalleled in the printing industry.

Although we offer our printing services to anyone, business to business has been our primary focus over the years. We have software in place to meet the growing demand for remote job management. Clients can access our facility online, and place variable data orders, like full-color business cards, or place static orders, like full-color pocket folders. We even offer fulfillment services, and have the warehouse capacity to manage your print inventory. You can upload files, track order history, and much more. Look for big changes in the near future though, as we look to significantly upgrade our online job management, online printing, and online estimating capabilities. We’re excited about the future at PPC! Check our site regularly for these upgrades, and join our Twitter feed and Facebook page for real-time updates.

Whether you’re looking for a targeted mailing list for a color postcard, or full-color business cards, or even a 64-page full-color catalog, we can produce it in-house. We complement our print production with a wide range of finishing options as well. As an example of our capabilities, we offer specialty UV coating options which can give your piece an extremely hi-gloss finish with a rich feel and superior protection. We also offer in-house custom diecutting services, and can provide custom dies, which will make your piece completely unique and original.

You’ll be happy to know that your printing is manufactured entirely in the USA. We can ship anywhere in the country, so whether you live right here in the Hampton Roads area, or the Outer Banks of North Carolina, or Northern Virginia and beyond, we deliver. Our high efficiency allows us to compete in markets beyond our local geography, and businesses can really benefit financially from our large volume.

Call toll-free today, at 877-547-1990, and find out what PPC can do for you!