This shorter article rounds off the mini-series dedicated to handling artwork for flexo printing within Adobe Illustrator using the Phantasm CS Studio and Publisher plugin. In this piece we will show a method of checking for areas of artwork which would be cut-off from the final result due to flexo printing’s ink drop-off levels.
TAC levels Correct flexo cut-off checking
It’s easy to make the mistake thinking that standard TAC (Total [Ink] Area Coverage) levels checking is appropriate for checking for cut-off levels for flexo printing. After all, TAC level checks are readily available in Phantasm CS Studio and Publisher (, Adobe Acrobat Pro and more.
Sadly, this would not be accurate. TAC levels are the accumulation of all inks placed on top of each other; ie. a CMYK print process could give a maximum ink coverage level of 100% x 4 = 400% at any one point. Apart from the fact that TAC level preview systems are geared towards informing the designer of ink coverage greater than a specified level (for this flexo printing check, we need to check for coverage less than a given cut-off value), we need to check individual ink channels, not the sum total.
For example, the following linear gradient (top) would not dip below even a 10% TAC coverage level as the gradient averages out at a constant 20% TAC level:
However, if a 5% ink drop-off level was applied via a cut-off curve, it may be seen from the lower gradient that two very clear steps occur. This is because each of the CMK channels get cut-off as they blend from a 20% tint to 0%.
Method of checking for flexo ink drop-off in Illustrator
Happily, the Phantasm CS Studio and Publisher Ink Coverage and full Separations tools are flexible enough to cater for this check when combined. Therefore it becomes possible to produce visual warnings to the Illustrator designer or operator that certain areas of artwork are going to be cut-off using a flexo print method. Once alerted, it’s then possible to use the techniques discussed in this mini-series to adjust the artwork.
For this example, we’ll be checking a portion of the Phantasm CS Drinks Carton example artwork (shown left) that can be found here in PDF form. This portion of the design makes use of 6 inks: CMYK plus two spot colors.
The first step is to fully separate of the original artwork using Phantasm CS’ full Separation system (not to be confused with the Quick Separations tool or the equivalent native quick separation panel found in Illustrator CS4 or above). To do this, ensure that the Phantasm CS Separations panel is displayed () and click on the button. This will create a new Illustrator document where each ink used in the original document is separated into layers, whereupon the Phantasm CS Separations panel will update to offer full viewing control.
In the Phantasm CS Separations panel, target a single ink separation to examine for cut-off levels by holding down and then clicking on the channel’s left-hand round button as may be seen below:
By holding down which clicking on the separation’s button, all other separations are removed from view. Notice that the Phantasm CS full separation system automatically desaturates the ink color allowing for clearer analysis of the tint levels found in that channel.
Next, open Phantasm CS Studio or Publisher’s Ink Coverage tool via and set the levels as follows:
Note that the most important value is the highlighted one, which should equate to the ink drop-off percentage value for the intended flexo print method (in this example, a realistic 3%). Set all other values higher, as per the example shown above.
Next, set the first ink level to a vivid bright color (the 0% level is always white) – in this case red was chosen by clicking on the color box and defining the color in the color picker window. Set the lower three ink levels to black.
Now, looking at the artwork Ink Coverage in the document window, the following may be seen:
Any area displayed in shades of red (or your chosen highlight color) represent areas of that particular separation in the artwork that will be cut-off using flexo printing. Areas of pure white are simply where no ink coverage for that separation occurs and isn’t of concern.
Close the Ink Coverage window, hold down and select another separation using the Phantasm CS Separations panel and repeat the process on all ink channels.
Return to the original document and adjust the artwork to correct the situation using techniques covered in this mini-series.
