The ISO 19593-1 standard describes the proposed method for storing or marking data in a PDF according to the processing steps for printed products.
In the packaging and label industry, it is common practice to use PDF files containing graphic objects used for printing as well as graphic objects used in downstream processing steps (cutting, creasing, varnishing, etc.). Thus, printed and non-printed objects can be quickly located within print data.
From a technical point of view, the graphic objects are, in simple terms, placed on different levels, the so-called OCGs (optional content groups), which can be made visible or hidden as required. For example, when rendering print data in a RIP, all OCGs with non-printing objects cannot be processed or non-printing objects such as cutting lines and the like can simply be transferred to the cutter without printing the actual graphic object.
More precisely, graphic objects are assigned to both a group and a type in the metadata. The group is not necessarily the same as the layer name that results. The name of the layer can be freely defined according to the the user's or company's working methods. For the groups Structural and Positions, types (predefined or freely defined) must be assigned. No types are provided for the remaning groups.
The ISO standard ensures that all content creators of print data properly label non-printing objects in the same way, which enables the highest possible degree of automation when outputting print data.
The following description shows which OCG should be generated for the specific graphic object and which label or mark the OCGs and their respective types should have so that the PDF file can be generated correctly according to ISO 19593-1 standards.
2. Processing Steps – Groups
According to ISO 19593-1, non-printed objects must be created according to their application on the following OCGs (layers) with the same or freely defined name. The following groups are available:
- Structural – Contains all objects that describe subsequent processing steps during final processing.
- Dimensions – Contains all objects that are used to specify sizes (lines, arrows and also captions (units of measurement)).
- Braille – Contains all objects that display Braille text and information.
- Legend – Contains all objects that are used to describe administrative e.g.: product information and technical information e.g.: control strips outside the printed product.
- Position – Contains all objects used to position information for various graphical and non-graphical elements.
- White – Includes all objects that need to be printed with white ink in order to improve the color of objects printed on metallic or transparent media.
- Varnish – Includes all objects that need to be finished with varnish.
3. Process Steps – Types
Objects assigned to individual Processing Steps that belong to a group should also be created as Spot Colors. In order to ensure that a function can be assigned to the object to which a Processing Step group has been assigned, the object should also be assigned a corresponding type. The name of the Spot Color does not have to be identical to the name of the type, since the identification of the type within the group is handled in the metadata. In the following list, the values for certain functions are briefly described for each group.
The Structural group has the most extensive requirements, since downstream processes can be very complex. The following types (functions) should be used for Spot Color objects:
- Cutting – Objects (path) of the Cutting processing step , which cuts the print product from the print sheet. Examples: cutting lines, punching lines, dielines, thru-cut, etc.
- PartialCutting – Objects (path) of the Cutting processing step , which is used to cut parts of the print product from the printed sheet. Examples: trimming, scratching, kiss-cut, etc.
- ReversePartialCutting – Objects (path) of the Cutting processing step , whereby areas of the print product on the back of the printed sheet are cut. Examples: cutting, scratching, kiss-cut, etc.
- Creasing – Objects (path) of the Creasing processing step, which indicate where the substrate is creased to allow subsequent folding. Examples: grooves, crease, scoring, etc.
- ReverseCreasing – Objects (path) of the Creasing processing step show where the substrate is creased on the back side to allow subsequent folding. Examples: backside creasing, backside scoring, backside groove, etc.
- CuttingCreasing – Objects (path) of the Creasing or Cutting processing step that indicate where the substrate is alternately creased or cut. Example: score/cut, crease/cut, etc.
- ReverseCuttingCreasing – Objects (path) of the Creasing or Cut processing step that indicate where the substrate on the reverse side is alternately creased or cut. Example: reverse creasing/cutting, backside crease/cut, etc.
- PartialCuttingCreasing – Objects (path) of the Creasing or Cutting processing step that show where the substrate is alternately partially creased or cut. Example: partial score/cut, partial cut/crease, etc.
- ReversePartialCuttingCreasing – Objects (path) of the Creasing or Cutting processing step that show where the substrate is alternately partially cut or creased on the reverse side. Example: backside partial creasing/cutting, backside partial cut/crease, etc.
- Drilling – Objects (area) of the Drilling processing step, which indicate where to drill a hole of a specific size. Example: drill, hole, etc.
- Gluing – Objects (area) of the Gluing processing step that indicate where glue is to be applied. Example: adhesive, glue, etc.
- FoilStamping – Objects (area) of the Foil Stamping processing step, indicating where foil is applied by hot glue stamping Example: foil stamping: hot adhesive foil, hot foil, etc.
- ColdFoilStamping – Objects (area) of the Foil Stamping processing step, which indicate where foils are applied by cold adhesive stamping (i.e. with glue). Example: cold adhesive foil, coldfoil, etc.
- Embossing – Objects (area) of the Embossing processing step, showing where embossing is applied. Example: embossing, etc.
- Debossing – Objects (area) of the Debossing processing step, that show where the debossing is applied. Example: debossing, etc.
- Perforating – Objects (path) of the Perforating processing step, that show where a perforation must be created. Example: perforation, perfo, etc.
- Bleed – Objects (path) of the Bleed processing step, which indicate the intended Bleed for printing. Example: bleed, trapping, etc.
- VarnishFree – Objects (area) that enclose the area where no varnish is allowed. Example: varnishfree, not varnish, no varnish, etc.
- InkFree – Objects (area) that enclose the area where no ink is allowed. Example: unprinted, color free area, no ink, ink free, etc.
- InkVarnishFree – Objects (area) that enclose the area where no ink or varnish is allowed. Example: unprinted, ink free, no ink, ink free, etc.
- Folding – Objects (path) of the Folding processing step that indicate where the substrate will be folded without making a crease. Examples: folds, folding, etc.
- Punching – Objects (area) of the Punching processing step that indicate where a punch in the intended size is to be made. Example: eyelets, brackets, grommets, etc.
- Stapling – Objects (area) of the Stapling processing step that indicate where staples of the intended size are to be stapled Example: staple, etc.
The Positions group which addresses positioning information for various graphical and non-graphical elements, has fewer types to choose from:
- Hologram – Objects (area) that show the position for holograms.
- Barcode – Objects (area) that display the position for barcodes.
- ContentArea – Objects (area) that indicate areas where text and other graphical elements may be placed.
- CodingMarking – Objects (area) that mark areas in which additional information not contained in the PDF file is printed on the packaging during additional processing. Examples: best before date, batch numbers, production dates and traceability codes, etc.
- Imprinting – Objects (area) marking areas where additional information (e.g. variable data) is applied to pre-printed elements.
3.3. Dimensions, Braille, Legend, White and Varnish
If the processing step group has a value other than Structural or Positions, a processing step type must not exist, or it must have a user-defined value. For simplicity, the name of the group should also be used for the name of the type, which means that searching for elements based on the type always produces a result.
While Braille is used to mark areas, the other groups can be used to mark individual objects such as lines, areas or text.
4. Color and Positioning
Objects such as paths and/or surfaces that are marked as processing step objects are also subject to corresponding rules regarding color and positioning.
- Objects that must not overlap the print product can have any color mode, overprint status, or transparency blend mode. They only have to be positioned completely outside the print product (including Bleed). Such objects usually belong to the Dimensions or Legend group.
- Objects that may overlap the print product must be created as overprinting Spot Color objects. Any name except All, None, Cyan, Magenta, Yellow and Black can be used as Spot Color name. Objects can be positioned anywhere within the MediaBox. Such objects usually belong to the group Structural, Positions, Braille, White or Varnish.