Using ONYX® Separation Control Tool

Contents:

•What is Separation Control?•Comparison to Basic/Advanced profiling workflow

•Advantages

•Using ONYX® Separation Control Tool•Enabling Separation Control

•Configuring the Workflow

•Anatomy of the Separation Control Tool

•Setting Ink Restriction

•Separation Control Tips and Tricks•Adjusting Curves

•When to adjust Variable Drop coverage and transitions

What is Separation Control?

What is Separation Control?Separation Control is an advanced tool for setting Ink Restrictions and configuring Variable Drop capable printers. It allows ONYX users extensive control over ink termination and coverage.

The advantages of using Separation Control over Ink Restrictions are in the ability to have non-fixed transition boundaries (ex: light ink to dark ink), and theability to set the rate at which inks are introduced, or decreased.

Also, when applicable, the Variable Drop and Multi-Drop control allows the user to define custom coverage curves, and thus add, move, and constrain the type of drops being used from 0% to 100% coverage.

Separation Control was implemented as a “Dot Pattern” in order to “ plug-in” to the profiling workflow, while maintaining the familiar Ink Restriction workflow in ONYX for basic users. NOTE: Separation Control is recommended for advanced users who have sufficient knowledge of the profiling process.

Separation Control vs. Traditional Ink Restriction and Variable Dot Workflows.NOTE: When using the Separation Control dot pattern, you will no longer have access to the standard ONYX Ink Restriction interface.Instead, the “Configure” button to the right of the Dot Pattern selection (Define Basic Mode Setup page) will bring up the Separation Control interface. This is where ink restrictions are made.

The following slide illustrates the similarities and differences between Separation Control and standard Ink Restriction setups.NOTE: When using the Separation Control dot pattern, the standard ONYX Ink Restriction interface is no longer used.

Separations (Ink Restriction)Unlike Ink Restrictions, Separation Control does not have fixed transition points for the introduction and transitioning of inks. For example: With Ink Restrictions, light inks are introduced at 0% coverage, peak at 50% coverage, and transition out to 100% coverage. Transition control in Ink Restrictions is limited to the rate of the transition out, from 50% to 100% coverage. All other points and slopes are fixed. Conversely, Separation Control gives the user unlimited control over the introduction, peak, and transitioning of ink, as well as curves, slopes, and shapes.

Variable Drop Unlike previous Variable Drop settings that consisted of static, non-configurable coverage curves, and drop by drop transitions. The variable Drop component gives the user complete control over total coverage, rate of coverage, and drop by drop transition (drop ratios)

Ink Restriction VS. Separation Control

Standard (Advanced) Ink Restriction and Separation Control comparison.Note how we are dealing with the exact same concept. The difference lies in the fact that you can move beginning, middle, and end points for ink channels anywhere you like in Separation Control.TIP: If you do not need to set specific transition points, or make VarDot adjustments you may want to use the standard Ink Restriction workflow.

Curves and Transition Points are fixed.

Curve Shape, Transition Points and Slopes are user configurable.

Using ONYX® Separation Control Tool

From the Home screen (in Media Manager), select “Configure Devices>Configure Printer Capabilities>Dot Patterns”Select the “OEM Dot Pattern” icon on the right-hand side of the screen and use the pull down menus to select “SepCtrl”

Enabling Separation Control

Using ONYX® Separation Control Tool

Because the Separation Control workflow replaces the traditional Ink Restriction view in ONYX Media Manager, it is recommended that you add, or modify the existing workflow using the Workflow Editor.

• From the Home screen, select Reports and Tools, then Customize Workflows.

• Select Add (or Edit), and follow the prompts to create and ICC based workflow.

• It is recommended that you choose the following options for the Separation Control workflow.

TIP: Adding the “Print Test Image” step to “Ink Restrictions” provides access to the “Measurement Tool” and will allow one to use spectral measurements to aid in setting ink levels.

Configuring the Workflow

Anatomy of Separation Control

Transitions on the Variable Dot Curves tab correspond to the dotted lines on the Separation tab. Altering the position on one tab isreflected on the other. This makes it easy to tell where the dottransitions occur when working on the ink levels (Separations tab).

Coverage Curve

Transition 1

Transition 2

Small Drops

Medium Drops

Large Drops

The Amount and Dot Size section gives feedback on the ratio of dotsbeing used. This will change with mouse position over the coverage area.

The Input and Output sections show feedback of node positions ofthe curves. Input defines the coverage area (Horizontal), While Output defines levels (Vertical).

TIP: It is possible to click and type in the Output fields.

Ink Restricting with Separation Control

There are two approaches in which to print and read swatches in conjunction with the Separation Control tool.

1. The Measure Tool option in the “Print Test Image” step. (Figure 1)2. Creating named Calibration, Media Model, and Linearization and using the information from the linearization to inform decisions about making

settings to the Separation curves. (Figure 2)

Figure 1 Figure 2

Making Ink Restriction Decisions*

*Typical approach to a CMYK printer with Light Cyan and Light Magenta using the Measure Tool.

Step 1:•Set the Light inks to zero. (Figure 1)•Set dark inks to start at zero coverage and ramp up to one hundred percent coverage. (Figure 2)TIP: You can remove nodes by clicking and pressing the Delete key, or dragging off the grid.

•The final result should appear as in Figure 3TIP: You may simply use the default Y or K curves and the “Copy” function to achieve the same result.

Figure 1 Figure 2 Figure 3

Making Ink Restriction Decisions [continued]

Step 2:From the Print Test Image dialog, select and print the Ink Restriction.tif file.

Making Ink Restriction Decisions [continued]

Step 2B:Visually inspect the print for any artifacts, or bleed in single channel patches. You will want to discard excess ink by setting the curves lower than the point at which the artifacts are visible.

Additionally, you may also use the Measure Tool to make measurements for Density, and/or Chroma (L*c*h*) to further refine your dark ink settings.Make a note of where you want to set the darks inks and return to the Configure Separation Control. (Please be sure to note the Yellow and Black maximums at this time)

Repeat the process of printing out the Ink Restriction Swatch for the light inks, making a visual inspection of the light ink ramps.

Because it is unlikely there will be artifacts, or a flattening in density, or Chroma (L*c*h*) in the light ink there may be minimal usefulness in taking measurements. It’s important to consider the amount of light ink needed to have smooth quarter and mid-tones. These will be the maximum light ink separation curve settings for light cyan and light magenta.

Setting the Ink Restrictions

Step 3: Using the values you selected for both Dark and Light ink, return to the separation control and set the curves as follows.Set the Dark Ink maximum value starting at zero coverage and ramp up to the value determined from the previous prints. (Figure 1)

Set the light curve so it peaks at one hundred percent ink, at fifty percent coverage. Then add a node on the up ramp at the point determined for maximum and click there. This will add a node on along the curve at the point of the maximum desired light ink.(Figure 2)TIP: You can simply click and type in the value on the lower left hand side of the screen.

Figure 1 Figure 2

Setting the Ink Restrictions [continued]

Step 3B:Now, click and drag the original light ink peak (node at 50% coverage) down to zero at seventy percent coverage. This will be the initial light ink curve. (Figure 1) Repeat this step for all light inks channels.

Next, change the Interpolation setting to Spline (Figure 2)TIP: Changing to a “Spline” curve will generally yield a smoother curves.

Figure 1 Figure 2

Setting the Ink Restrictions [continued]

Step 3C:Click on the dark ink curve just prior to the point where light ink peaks, and add a node. Drag this node down to zero. This will be the initial dark inkcurve. (Figure 1) Next, change the Interpolation to Spline. (Figure 2) Repeat this procedure for all dark ink channels. Congratulations! You have a working curve setup*.

*While this is a typical good curve setup, it’s not unusual for the first characterization of a printer to take several attempts. This is because each printer’s light and dark inks will differ in their optimum transition points from light to dark ink. Conversely, the linearization step does a good job of dealing with minor spikes in the combined dark and light ink.

Figure 1 Figure 2

Separations [tips and tricks ]

•Ctrl-Z will allow a single level of undo in the Separation Tool.•You can remove nodes by clicking and pressing the Delete key, or dragging off the grid.•You can also Export to save various configurations and Import them as a way to get back to a known state.•Values can be typed into the “Output” section to fine tune the movement of nodes made with the mouse.•Nodes that have been highlighted by clicking with the mouse can be moved using the arrow keys on the keyboard, allowing increased precision.•Curves can be copied between channels saving time configuring complex setups. (Figures 1 and 2)

Figure 1 Figure 2

Variable Dot Curves [tips and tricks]

While the default Variable Drop Curves (Figure 2) are adequate for most applications, on occasion the drop to drop transition may be too abrupt. This is typically manifests as flats spots in the Calibration readings, and subsequent Linearization (Figure 1)

Figure 1 Figure 2

See next slide for recommendation

Variable Dot Curves [tips and tricks]

In this example a “toe” has been added to Transition 1 (Figure 2) The result can be seen in the subsequent Linearization. (Figure 1)For the purpose of this example we have added a “shoulder” to the Coverage curve, as well as toe to the medium to large transition.

Figure 1 Figure 2

Adding a “toe” helps alleviate the abrupt transition