What about Double-Strike?
Some printers have ink configurations that allows for printed dots to be "struck" a 2nd time. Regular ink configurations are "Single-Strike" and use one pass per channel to obtain maximum coverage. In some cases one strike (or pass) is not sufficient, so ink configuration with "Double-Strike" allow for a second pass which lays down 200% ink. This means the printer will put down more ink to obtain complete coverage or higher density. The ink configuration is usually labeled DS.
If you have this type of printer and are using this ink configuration, you will see on the Advanced Ink Restrictions tab a second field options such as the following example for the Cyan settings:
lc = 80 (Cyan Light Ink Default Setting is 80% of Dark Ink Value)
C1 = 100 (Cyan Dark Ink Single-Strike)
C2 = 100 (Cyan Dark Ink Double-Strike)
In this case having C1 set at 100 means that 100% of the dots to be printed are "struck" once and C2 at 100% means that dots are doubled. By using the C2 setting we can increase the number of dots that are "struck" a second time.
To determine Ink Restrictions using Double-Strike
You will want to set both C1 and C2 to 100% and lc to 0%, then use the drop down list to choose the Ink Restriction Swatch and print the swatch with these values.
Use the same method for determining the desired dark ink restriction percentage as you would with a single-strike printer, then multiple that percentage by 2. For example: if you choose to select the 72% as your dark ink restriction, you would use 144% (72 x 2 = 144) ink to achieve your desired ink restriction for Cyan.
Setting C1 to 100 and C2 to 44 would cause 100% of the printed dots to be "struck" one time and then a randomized selection equal to 44% of the original dots would be "struck" a second time. This would increase the amount of ink used to give better coverage and increase the optical density. Typically it is preferable to use 100% of the first strike ink coverage before increasing the value for second strike coverage, but you can split the difference if you prefer and use 72% for both C1 and C2. If you find that you do not need the second strike for coverage consider using the regular ink configuration.
Repeat for each channel to set the dark ink values.
Setting Light Inks with Double-Strike
You would still set the light inks based on the single strike percentage. Water based inks start at 80% of the dark ink value and Solvent/UV at 50%. In this case since the C1 is 100%, the lc would be set to 80%. Another example would be if your C1 is 72% and your C2 is 0%, then your lc would be 58% (72 X .8 = 57.6).
Do not use the Macros buttons for setting light inks with a double strike - this will take the percentage of the C2 value (theoretically the darkest level) and change both the C1 value and the lc value.
Make your changes manually into the software interface and use the drop-down list to choose the Ink Restriction Verification Swatch. Print the file to verify your results before continuing paying close attention to the upper left-hand side of the swatch. This area helps shows issues if the light ink is set too high.
As of this writing there are no printers that use multiple size or variable size dot technology in conjunction with "Double-Strike" technology.
