Nesting Mode

In this Article we'll learn:

  • How to arrange Print Items on the imposition sheet to optimize space savings
  • Which settings can be applied when Nesting Mode is active

1. General Overview

Using Nesting mode, Print Items are arranged in a way which saves material (Substrate) depending on the size of the impose sheet and the number as well as the quantity of the Print Items to be printed. Nesting typically reduces waste and optimizes the layout of Print Items to make the finishing process easier when post processing.

Arranging Print Items of different or equal dimensions on a impose sheet in a space-saving rule-based manner is called Nesting. If you want to create a Nesting for Print Items using the same dimensions on an impose sheet, proceed as follows:

  1. Open the Impose Editor and select Nesting Mode.
  2. To start the Impose Editor, you can either select Automation > Impose Editor and then select the Impose Mode Nesting or you can open an existing Production Job and select the Impose [1] tab. In the Impose tab, you can select Nesting [2], which opens the Impose Editor using Nesting Mode.

Figure 1: The Impose tab offers the possibility to use various impose modes in the Workflow.

  1. Select your desired Print Items to be imposed under the Print Items tab.
    If you have started the Impose Editor via the menu item Automation > Impose Editor, you need to add a Print Item to an empty Production Job. The fastest way to do this is to use the File Manager. If the Impose Editor was started via the Impose tab of a Production Job, the Print Items contained in the Production Job are already selected.
  2. Enter a size for the sheet by entering a Width [3] and a Height [4]. Activate Trim [5] to reduce the surface area that would otherwise be unprinted. If a larger surface area is needed for the imposition, enter a maximum set height (in our case 1000 mm) which will be automatically applied. If a maximum Height is entered then activating the Trim function is no longer necessary.

Figure 2: The action bar as seen in the Impose Editor when Nesting Mode is selected and custom values are entered.

  1. Select the desired parameters under the Artboard Settings [6] tab for the Nesting. The specific parameters can be found under the sub-panels: Settings, Nesting Options and Bleed.

Settings

In the Settings sub-panel, you can determine general parameters that have a core affect on the imposition. The following options are available:

  • Imposition based on [7] – This setting determines whether other settings under the Nesting Options sub-panel are based on the ImageBox or the ImageBox + Bleed. Typically the ImageBox is used within the label industry and ImageBox + Bleed is used in large format productions.
  • Imposition aligned to [8] – This setting allows the user to define on which corner or edge Print Items should be aligned to on the sheet.
  • Auto Margin [9] – By activating this checkbox, a Margin is automatically generated, which ensures that all Marks and Captions lie completely on the sheet. Deactivate the checkbox only if Marks or Captions should intentionally overlap the sheet.

Nesting Options

Use these settings to define how Print Items should be imposed on the sheet. The following options are available:

  • Strategy [10] – The Strategy options determines the placement method for Print Items when nesting.  There are four strategies available:
    • Substrate Optimized – Places Print Items as optimally as possible to reduce the total amount of unprinted space on the sheet. Underproduction of individual Print Items may occur.
    • Keep exact ratio of copies – Places Print Items on the sheet in proportion to the entered number of copies to be produced. This strategy should be used when it is vital to not over- or underproduce Print Items. Print Items that are not placed on the sheet because of a lack of space, will not be included in the imposition.
    • Allow Overproduction – The sheet will be filled with Print Items in proportion to the number of copies. This may result in overproduction of Print Items in proportion to the quantity entered.
    • Force number of copies – If the total number of copies can be placed, then only those Print Items will be placed on the sheet. Some Print Items may be missing in the imposition with this option.
  • Layout [11] – This options allows the user to select either By Row or By Column. Both options are available in the pop-up menu.
  • Arrange [12] – This option helps determine how Print Items should be arranged on the sheet based on the production needs. Three options are available:
    • Keep Print Items together – If multiple copies of single items need to be produced they will be kept together on the sheet.
    • Consider Print Item sequence – With this option Print Items are placed one after the other based on the order of the Print Items under the »Print Items« tab.
    • Use only one Print Item per Column/Row – Only a single Print Item will be used per Column or Row.
  • Rotation [13] – This options determines the rotation of individual Print Items when paced on the sheet. Four options are available:
    • Non-uniform Rotation – Print Items can be oriented in different directions on the sheet, which can result in improved utilization ratios.
    • Uniform Rotation – All Print Items are placed using uniform rotation. The algorithm determines whether they are rotated either 0° or 90°. The algorithm always tries to minimize the amount of un-printed area.
    • Rotate 0° – All Print Items are placed using their native orientation.
    • Rotate 90° – All Print Items are placed 90° clockwise according to their current orientation.
  • Add additional space for rotated items [14] – This adds additional space based on the size placed Marks, in addition to the entered horizontal or vertical spacing. This option should be activated if Marks are used.
  • Horiz. and Vert. Spacing [15] – Here you can define both horizontal and vertical spacing between the Print Items. Note that the spacing is created based on the Impose based on option selected.
  • Mode [16] – This option determines which calculation method is used when imposing Print Items that have different dimensions. The calculation methods available are: Fit Area, Fit Long Side, Fit Short Side, Top Left and Contact Point Rule.

Figure 3: A Nesting imposition showing the Artboard Settings tab and the available settings.

Bleed [17] – Determines how much of the existing Print Item Bleed will be printed.

  1. After you have created your desired imposition, you can now add any Marks, Captions, Lines or Grommets necessary for production.
  2. To do this, switch to the Marks tab [18]. Here you can add any of the options mentioned above.

Marks [19] – Select your desired type of Mark and determine where and in which size and color it should be created. The position and type of Mark is largely dictated by the types of finishing equipment that will be used in post processing. Typically in Nesting CropMarks are added to Print Items that contain a partially white border which makes it easier to recognize the area that needs to be cut.

Captions [20] – Select your desired Caption and determine where and in which form it should be placed on the sheet. In the case of Nesting, the Order Number, Print Item Name and the number of copies can be very helpful to identify individual Print Items on the sheet.

Lines [21] – Select your desired Line type and specify where and in which size and color it should be placed. Typically in Nesting additional printing lines are only needed if cutting lines for Print Items need to be printed on a 5 meter wide roll, which makes manual cutting of the Print Items much easier.

Grommets [22] – Select your desired Grommet type and specify where and in which size and color it should be placed. If Grommets have not already been applied to the Print Item in the pre-press stage, they can be placed dynamically when imposing, and are more common when creating Tiling impositions but are also used when Nesting.

For more information about these four Marks, take a look at the article Marks, Captions, Lines and Grommets.

Figure 4: The Marks tab contains four different types of Marks, all of which can be used in Nesting Mode.

PMS WebGui :: Print Data
  1. Under the Finishing [23] tab, you can select the Create Dielines [24] option if required. This creates a Dieline for each individual Print Item based on the ImageBox. The following additional options are available:
    • Position [25] – Select ImageBox + Bleed if the Dieline should be applied to the expected bleed. ImageBox is selected by default and is almost always the right choice.
    • Corner Type [26] – Depending on the type of Cutting Device used, you can select whether the corners should be Beveled or Rounded. If a corner needs to be cut, a value of 0 mm should be entered when Beveled is chosen.
    • Weight and Offset – Define the weight of the Dieline and enter the desired Offset of the line based on the position selected.
    • Technical Color [27] – Here you can select a System-wide defined Spot Color. If the Spot Color you desire is not displayed, it must first be created under the menu item Color > Manage Spot Colors.
    • Overprint [28] – As Technical Colors almost always need to be overprinted, this checkbox should only be deactivated in certain cases.

Figure 5: The Create Dieline sub-panel of the Finishing tab.

Impose Editor
  1. If you are satisfied with the current settings and want to apply these settings to additional Jobs, we recommend that you save these settings using an Impose Template.
  2. You can now save the imposition.
    • If you have opened the Impose Editor using the Impose tab from within a Production Job, you can save the imposition by clicking on Save in the top right-hand corner. The Save Imposition dialog is not displayed, because all parameters contained within the Production Job have already been saved.
    • However, if you have opened the Impose Editor via the menu item Automation > Impose Editor, you can save the imposition by selecting Save or Save as in the action bar. When saving the imposition, a new Production Job is created.  
  3. By saving the imposition, a Save Imposition dialog will open. You have the following choices in this dialog:
    • Job Name [29] – Enter either a number or name for the Production Job here. Additional information about the Production Job can be saved in the Comment section below.
    • Output Configuration [31] – If you opened the Impose Editor via the menu item Automation > Impose Editor and have not assigned an Output Configuration, you can now select one when saving the imposition.
    • Split Reference [30] – If a Production Job was created from an Article, Order or the File Manager, this checkbox is displayed for all Print Items that originate from these sources. If this checkbox is activated, the Print Item will be duplicated and copied into the new Production Job when it is created. This removes the 1:1 reference to the Article or Print Item in an Order.
  4. Click on Save to complete the imposition process.

Figure 6: The Save Imposition dialog.

Impose Editor

3. Nesting Options

The following descriptions below illustrate the result of selecting certain options in the Impose Editor.

3.1. Layout

In the Layout sub-panel (which is only available if using Print Items of identical dimensions in the Nesting), you can choose between By Row or By Column.

3.1.1. By Row

If the option By Row is selected, the algorithm starts placing Print Items on the upper-left edge and adds additional Print Items row by row, depending on which option is selected under Arrange.

Figure 7: A Nesting imposition with By Row and Keep Print Items together chosen.

3.1.2. By Columns

If By Columns is selected, the algorithm starts placing Print Items on the upper-left edge and adds additional Print Items column by column, depending on which option is selected under Arrange.

Figure 8: A Nesting imposition with By Column and Keep Print Items together chosen.

3.2. Arrange

Under the Arrange sub-panel (which is only available if you use Print Items with identical dimension in Nesting), you can choose between Keep Print Items together, Consider Print Item Sequence and Use only one Print Item per column/row.

3.2.1. Keep Print Items Together

If Keep Print Items together is chosen, Print Items that need to have multiple copies printed are kept together in the imposition. In our example, six Print Items, each with different amounts of copies per item, the visible number on the Print Item indicates the number of copies that have been assigned to the Print Item. The imposition is started by placing items in the upper-left corner respecting the number of copies required by the first Print item. This places the Print Items in the order that they are displayed in the »Print Items« tab. After that the number of copies from the second Print Item is placed until complete.

You can change the ordering of the Print Items to be imposed by moving them in the Print Items tab.

Figure 9: A Nesting imposition using Keep Print Items together with Print Items tab open.

3.2.2. Consider Print Item Sequence

If Consider Print Item Sequence was selected, Print Items will be placed one after the other based on the order in the »Print Items« tab. In our example, six Print Items containing different numbers of copies ( in this case, the number displayed on the Print Item indicates the number of copies), have been added to the imposition. The imposition starts at the top-left edge with the first Print Item listed in the »Print Items« tab. After that, all Print Items in the »Print Items« tab are added one after the other. This sequence is then repeated until the selected number of copies is achieved.

You can determine the order in which the Print Items are imposed by changing the order of the Print Items in the »Print Items« tab.

Figure 10: A Nesting imposition with Consider Print Item Sequence selected and the Artboard Settings tab open.

3.2.3. Use only one Print Item per Column/Row

If Use only one Print Item per column/row was selected, single Print Items will be placed per column/row.

Figure 11: A Nesting imposition with Use only one Print Item per column/row selected under the Artboard Settings tab.

4. Special cases for Nesting

Additional functions are available in Nesting Mode which may help the user more efficiently place/impose Print Items in special cases.

4.1. Uniformly aligning individual Print Items in Nesting

In the corrugated board and textile printing industry, when printing certain items, it may not be possible to rotate mixed items differently. For example, in the corrugated board industry Print Items have been designed to be printed either with or across the flute direction of a substrate, or in textiles when rotating Print Items and then printing them would result in extreme colour differences. For both the reasons mentioned above, we offer the possibility to rotate individual items uniformly. Proceed as follows:

  1. Create a Nesting with several Print Items.
  2. Under Nesting Options, under the option Rotation, select Non-Uniform Rotation. This option may cause individual Print Items within the imposition to be rotated due to the way the Nesting optimization algorithm works. In our example in Figure 12, the second Print Item is imposed on the sheet differently (it is rotated).
  3. The symbol [32] below the Print Item thumbnail indicates whether the Print Item inherits it's rotation from the Nesting Options and therefore must not be rotated uniformly.

Figure 12: A Nesting imposition with different rotations applied to optimize material usage.

  1. Click on the symbol [33] to determine the current orientation of the rotation for each Print Item. When selected, it overrides the value applied under the Rotation sub-panel settings under Nesting Options. Click on the symbol three times to cycle through the available options:
    • From Nesting Options – The current Print Item rotation is based on the value selected under Nesting Options.
    • Uniform Rotation – The Print Item is rotated uniformly in the imposition. 0° or 90° rotation options cannot be selected.
    • Non-uniform Rotation – The Print Item can be rotated differently within the imposition even if rotation is set to 0° for all Print Items under Nesting Options.

When Nesting, always pay attention to the rotation symbol below the Print Item thumbnail. You can also make sure that no Print Items have had a Dieline (Technical Color) added previously [34] as adding two Dielines will not create the expected results. If you see a colored sphere under the Print Item thumbnail than you can be sure it contains a Technical Color and therefore most likely a Cutting Line of some sort.