The press tool is a simple program that gives the press operator quick access the information needed to ensure the press run has consistent color. The Press Tool is easy to use and displays the information in a format that is simple and intuitive.
Before we go into the details of the tool, lets take a brief look at what kind of information is being presented.
The instrument measures the density along the length of the bar you put in to be measured. These numbers give an indication of how much light is reflected back by the color, which is related to how much ink is put down. In general, the more ink you put on the paper, the higher the density goes. When the right combination of Cyan, Magenta, and Yellow are put on at the same time, you get an even gray color. This is called being in balance. If the wrong amount of ink is put down, then instead of a gray bar you get a bar with a color tint to it. This is out of balance. The densities numbers were designed so that when they are about the same, you will have an even gray. When one is higher or lower than the others, you get a bar with a hue to it.
But there is more to it than that. You can put on a lot of ink in the right proportion and you will get a gray. You can print a little ink in the same proportion and also get a gray (the gray will be darker in the first case, but still gray). So it is important not only that you print the ink in the correct proportion, but also print the correct amount. We refer to keeping the correct amount of ink on the page as keeping the level correct. So the goal in the printing is to print at the correct level and in balance.
It is possible to print in balance, but at the wrong level. This means more ink than is necessary is being applied, but the relative amounts of C, M, and Y are good enough to keep the gray in balance. It is not possible to be out of balance but have all the inks at the right level. To be out of balance mans at least one ink will be high or low.
The Press Tool tracks this balance for you automatically, telling you if you are in or out of balance. It also tracks the individual ink levels so you can know if the levels are correct. Level Indicators show the level for the individual inks, whether they are high or low. And a balance indicator indicates if the ratio of the inks is incorrect and throwing the whole bar out of balance.
To make a scan open up the section you want to measure, slide it into the track so that lights shining in the track are right in the middle of the bar. To make it easier to adjust the paper, press the button on the instrument. This will turn on the vacuum and hold the paper in place while you get it aligned. Once the paper is in the correct position, press the button again and the scanning densitometer will start reading the information on the page.
As the instrument scans you can tell the software what it is scanning by first selecting the Scan ID from the list. This sets up all the press and paper parameters for the sheet. Then by entering the section and page you tell the software on which the bar is located. The software assumes even pages are on the left side, and odd pages on the right, but you can override this by pressing the Right and Left buttons. If you happen to be printing a tabloid then right and left don’t matter, and all you will see is a button labeled “Tabloid”. Once these are entered press OK, you are done!
When the scan is complete the information will be displayed on the screen. It will tell you what the densities are for each zone, if you have the ink levels correct, and how the gray balance is doing. A full report on the page color in only a few seconds!
If for some reason you want to stop a scan before it has completed, then you can press the “Cancel” button on the scan information screen, or press the button on the instrument. Either one will stop the current scan and prepare the software to start the next one.
The first thing to notice is that most of the screen is divided into eight sections. These are the zone boxes and correspond to the zones on your press. Below the zone boxes and to the left is the scan identification information. This includes when the scan was taken, which Scan ID was used, and the targets for the scan. On the bottom left of the box are some basic controls the pressman can use to view and review the data.
In each of the zone box you have five elements: the zone number, the Balance Indicator, the CMY Level Indictors, the Level and Balance Gauge, and the Density Readings (Figure 1).
The first element is the zone number. This indicates which zone on the press the data represents.
The next element is the Balance Indicator. This indicator is shown when the CMY balance is out of tolerance. As you can see above, on the main screen shown above, zones 4, 5 and 6 are out of balance. The third element is the CMY level Indicators. These are the six boxes (three above and three below the level gauge) that tell you if the density reading for the ink is too high or too low. When a level indicator above the gauge is lit, then the density of the corresponding ink is too high. If one below is lit, then the ink density is low. So again looking above we see that in zones 6 and 7 the yellow ink is high. In zones one through four, all the inks are low, and in zone 5 only the cyan and magenta inks are low.
The fourth element is the Level and Balance Gauge. The Gauge gives you a graphical view of how the balance and level is on the press. When the arrow on the gauge points to the zero, it indicates that that density is right on target. If it is above the zero the density is high, and below it is low. Whenever the arrows are far apart, the balance is in trouble. If the arrows are close but out of the green the balance is good but the level is off. Bottom line: if all the arrows are in the green then the color is both at the right level, and is in balance.
The Scan Identification Information shows the Date and Time of the scan, the Section and Page, the Scan ID and the Density targets for the scan.
The format of the date and time will mach what is set for the Windows Operating System. So if you would like to see the time using the 24-hour clock, or some other variation, you can change it using the Windows settings.
The Section and Page tells what was entered on the Scan Screen. The Scan ID information and the corresponding targets are set using Settings Tool. These are shown here for information, and cannot be adjusted from the Press Tool once the scan has been completed.
The View and Review controls allow the press operator to see the data in four different ways, and to review data previously scanned.
The Densities buttons will toggle the Density Readings in the Zone Box between showing the actual density reading and the difference from the target. When “Actual: is selected, the densities will be what was actually measured by the instrument. When Difference is selected, the values shown will have the target densities subtracted from the measured densities. For example, if on a scan the target values is 0.60D and the measured density is 0.62D, then the “Actual” would show 0.62 and “Difference” would show to 0.02. Similarly, of the reading was 0.58D, then “Actual” would show 0.58 and “Difference” would show to -0.02.
The Mode buttons switch between the Gray Balance mode and the Black ink only mode. In the Gray Balance Mode the Zone Boxes show the CMY densities that make up the gray (See Figure 1 above). In Black Mode the Zone Boxes show only the black density. This is useful if you are printing a single color and want to ensure the ink is being layed evenly across the entire sheet.
There are two types of Calibration needed by the ATD News system. The first is the calibration of the scanning head. Since everything needed to do the calibration is built into the instrument, this will occur automatically (the time interval between calibrations can be set in the system administrator using the Setting tool). However if you want to initiate a calibration manually you can do so by pressing the F6 key.
The second type of calibration is a track calibration. The scanning instrument looks for the edge of the paper by noticing that it is no longer over the scan track. However to do this it must know what the scan track “looks” like. The track calibration is where the scanning head learns about the look of the track. This calibration should not be needed often. If you keep the scanning track reasonable clean by wiping it down daily, then the scan head should not have trouble. However if you replace the scanning head, or wiping the track does not seem to help, then a track calibration may be necessary.
When performing either calibration the software will walk you through the steps. Both are quick and easy, but it is important that you follow the instructions on the screen. If done incorrectly, a calibration can make the instrument inaccurate or stop working until corrected.
The Scan Screen allows the press operator to enter the Scan Identifier, the section and the page number for the scan, and to indicate on which side of the sheet the bar is located.
The Scan ID specifies the specific characteristics of the scan (The Scan ID information is set using Settings Tool). The right and left buttons indicate on which side of the sheet the gray bar is positioned. If the Scan ID setting is set for a tabloid scan, the “Left” and “Right” buttons are replaced by a single button labeled “Tabloid”.
To enter the section and page, press the buttons. The “-“ is used to separate the two items. Or if this is too difficult, the quick pick list on the left shows the last 25 section/page combinations used so they can be re-used with a single press.
To make the entry of the scan information as simple as possible, the software assumes that pages with odd numbers are on the right, and pages with even numbers are on the left. When you enter a page number the software will automatically select the corresponding side. However if you need to override this behavior, then manually selecting “Left” or “Right” will “stick” and the override will be used instead.
If a mistake is made when entering the section or page, the “ß” button can be used to delete the last character, or the “Clear” button will remove all the characters.
Finally, pressing “OK” will accept the information entered and record it with the scan. Pressing “Stop” will stop the scan and all the scan information and scan data will be lost.
If there are pinholes in the color bar this can affect the density readings. The instrument averages many reading over the width of a zone. If there are only a few pinholes the effect will probably not be seen. However if there are a lot then the black track will be seen through these holes. And it will generally cause an increase in the density readings for the zone.
To read a bar that is not gray or black, such as a red or green bar, no special steps need to be taken. To avoid having the balance indicators show problems, first measure a representative sample of the bar, and then create a Scan Identifier with the proper density settings for the bar. Since neither the inks nor the paper is perfect, there will always be some density reading on CM and Y. For colored bars one or two of these will dominate, but setting the values for even the non-dominate filters will allow the software to be used without false alarms.
The software tries to filter out zones in which there is only paper, however since newsprint or pictures can look just like a bar this cannot be relied upon. If the bar only covers part of the page, the zones that are not covered can be ignored.
Always put the paper reading left to right. This makes the Right/Left determination work correctly. If you need to read the top or middle of the section, keep reading left to right and lip the section in the track from the front side. Move it up through the center and align the bar with the LED’s.
The scanning instrument will read around 5 samples per inch of bar. All the reading within a zone are averaged, and the results shown on the screen. Readings that span zones are not used in the average calculation. Since bars can vary greatly in color not only across the sheet, but along the sheet as well, the consistent placement of the bar on the track lights is important for consistent readings.