They are not nearly as sexy as all those computer-driven engines we work with. And after all, if you’ve seen one plate, you’ve seen them all.

Not so, say the pressmen I’ve talked to. A plate affects register, dot gain, makeready, and press handling. They are the rubber that hits the road. Think of them as being as important as the tires you would choose for your Porsche.

In the newspaper business, productivity is always a No. 1 consideration when choosing technology. Plates are as much a factor of productivity as the platesetter or the press.

You can have the most efficient workflow in the business, but without the appropriate plates, it’s like driving a high-performance car on re-treads. All the productivity you gained from your system will be irretrievably lost in the end.

Rules of the road

Quality — We think of plate quality in terms of resolution, expressed in rated lines per inch. But quality should be qualified in terms of the actual achievable performance for the type of print job. And that depends primarily on the plate’s screen-rendering capability, which is represented in dot percentages. The higher the required screen ruling, the more difficult it is to render fine highlight and shadow tints. Jobs that require 133 to 150 lines per inch typically require 3 percent to 97 percent rendering, while 175 to 200 or more lpi work usually requires 2 percent to 98 percent.

Another important factor affecting quality is linearity, which is the flatness of the required transfer curve. The better the linearity, the less you will need to correct for linearization. Significant linearity corrections can cause noise and limit the number of gray levels the plate can render.

Exposure latitude — The wider the exposure latitude, the more stable the dot — a dot that won’t be affected by overexposure or underexposure. That will give you more predictable output.

Processing stability — Today’s digital plates require chemical processing, and every plate technology requires its own equipment and chemistry. Look for a process with few variables and wide latitude. Do not underestimate the importance of processing stability in overall plate predictability and reproducibility.

Processing fluctuations can change even the slightest image characteristics. And that will require costly and time-consuming remakes.

Run length — If you print a number of editions or titles with various run lengths, choose a plate that can be baked. Baking will extend the run life of a plate dramatically — from 250,000 to over 1 million. This way you can use a single plate for a variety of jobs.

Safelight conditions — If you are using a system that requires manual operation, consider the safelight requirements, as some are more comfortable to work under than others. Safelight conditions can vary from no light to white light.

Thermal plates — There are a number of new choices for thermal platesetting. There are ablation, non-ablation, and processor-free. Ablation systems can slow you down. They require a special process for removing the debris left in the non-image areas. Some users say dot gain can be an issue with some thermal plates.

Kicking the tires

Take your plates for a test ride. It is important to monitor how different plates interact with your system. Best of all seek the advice of your suppliers. The best advice will come from a company that manufactures both the equipment and plates and understands all the nuances of their interaction. After all, it takes more than a shiny new car to make a good impression.

Reader response

In my last column, I addressed the merits of computer-to-plate and computer-to-film systems. Based on input I received from both users and manufacturers, I wrote that thermal systems are generally slower than visible light.

An interested reader e-mailed to say he uses a thermal system that produces a plate in nearly half the time of his visible light platesetter.

As is the case with evolving technology, product specifications change every day. It is certainly possible that newer thermal systems are faster than older visible light system. So it is important to compare same-generation systems to make an accurate assessment. And then take every factor into consideration, including processing time.

Your decision should not be made on speed alone. Fast will do you no good if the system falls short on repeatability and reliability.

Funny thing about productivity. It involves so many factors. And to be realized, it has to happen from one end of the workflow to the other — from think to ink.