Print and save transparent artwork

When you save an Illustrator file in certain formats, the native transparency information is retained. For example, when you save a file in Illustrator CS (or later) EPS format, the file contains both native Illustrator data and EPS data. When you reopen the file in Illustrator, the native (unflattened) data is read. When you place the file into another application, the EPS (flattened) data is read.

If your document or artwork contains transparency, to be output it usually needs to undergo a process called flattening. Flattening divides transparent artwork into vector-based areas and rasterized areas. As artwork becomes more complex (mixing images, vectors, type, spot colors, overprinting, and so on), so does the flattening and its results.

Flattening may be necessary when you print or when you save or export to other formats that don’t support transparency. To retain transparency without flattening when you create PDF files, save your file as Adobe PDF 1.4 (Acrobat 5.0) or later.

You can specify flattening settings and then save and apply them as transparency flattener presets. Transparent objects are flattened according to the settings in the selected flattener preset.

File formats that retain transparency

When you save an Illustrator file in certain formats, the native transparency information is retained. For example, when you save a file in Illustrator CS (or later) EPS format, the file contains both native Illustrator data and EPS data. When you reopen the file in Illustrator, the native (unflattened) data is read. When you place the file into another application, the EPS (flattened) data is read.

When possible, keep your file in a format in which native transparency data is retained, allowing you to make edits as necessary.

Native transparency data is retained when you save to the following formats:

• AI9 and later

• AI9 EPS and later

• PDF 1.4 and later (when Preserve Illustrator Editing Capabilities option is selected)

Illustrator flattens artwork when you perform any of the following actions:

• Print a file that contains transparency.

• Save a file that contains transparency in a legacy format such as native Illustrator 8 and earlier, Illustrator 8 EPS and earlier, or PDF 1.3 format. (For the Illustrator and Illustrator EPS formats, you can choose to discard transparency rather than flatten it.)

• Export a file that contains transparency to a vector format that does not understand transparency (such as EMF or WMF).

• Copy and paste transparent art from Illustrator into another application with both the AICB and the Preserve Appearance options checked (in the File Handling & Clipboard section of the Preferences dialog box).

Set transparency flattening options for printing

Transparency Flattener options

You can set Transparency Flattener options when creating, editing, or previewing flattener presets in Illustrator, InDesign, or Acrobat.

Highlight (preview) options

Disables previewing.

Highlights the areas that will be rasterized for performance reasons (as determined by the Rasters/Vectors slider). Keep in mind that the boundary of the highlight area has a higher probability of producing stitching problems (depending on the print-driver settings and the rasterization resolution). To minimize stitching problems, select Clip Complex Regions.

Highlights the objects that are sources of transparency, such as objects with partial opacity (including images with alpha channels), objects with blending modes, and objects with opacity masks. In addition, note that styles and effects may contain transparency, and overprinted objects may be treated as sources of transparency if they are involved in transparency or if the overprint needs to be flattened.

Highlights all objects that are involved in transparency, including transparent objects and objects that are overlapped by transparent objects. The highlighted objects will be affected by the flattening process—their strokes or patterns will be expanded, portions of them may get rasterized, and so on.

Highlights all linked EPS files that are affected by transparency.

Highlights all placed content affected by transparency or transparency effects. This option is useful for service providers who need to see graphics that require attention to print properly.

Highlights all patterns that will be expanded if involved in transparency.

Highlights all strokes that will be outlined if involved in transparency or because Convert All Strokes To Outlines is selected.

Highlights all text that will be outlined if involved in transparency or because Convert All Text To Outlines is selected.

note: In the final output, outlined strokes and text may appear slightly different from native ones, especially very thin strokes and very small text. However, the Flattener Preview doesn’t highlight this altered appearance.

Highlights text and strokes that have rasterized fills as a result of flattening.

Highlights objects and intersections of objects that will be rasterized because there is no other way of representing them in PostScript or because they are more complex than the threshold specified by the Rasters/Vectors slider. For example, the intersection of two transparent gradients will always be rasterized, even if the Rasters/Vectors value is 100. The All Rasterized Regions option also shows raster graphics (such as Photoshop files) involved in transparency, and raster effects such as drop shadows and feathers. Note that this option takes longer to process than the others.

Transparency Flattener Preset options

Specifies the name of the preset. Depending on the dialog box, you can type a name in the Name text box or accept the default. You can enter the name of an existing preset to edit that preset. However, you can’t edit the default presets.

Specifies the amount of vector information that will be preserved. Higher settings preserve more vector objects, while lower settings rasterize more vector objects; intermediate settings preserve simple areas in vector form and rasterize complex ones. Select the lowest setting to rasterize all the artwork.

Note: The amount of rasterization that occurs depends on the complexity of the page and the types of overlapping objects.

Rasterizes all objects, including images, vector artwork, text, and gradients, to the specified resolution. Acrobat and InDesign allow a maximum of 9600 pixels per inch (ppi) for line art, and 1200 ppi for gradient mesh. Illustrator allows a maximum of 9600 ppi for both line art and gradient mesh. The resolution affects the precision of intersections when flattened. Line Art and Text Resolution should generally be set to 600‑1200 to provide high-quality rasterization, especially on serif or small point sized type.

Specifies the resolution for gradients and Illustrator mesh objects rasterized as a result of flattening, from 72 to 2400 ppi. The resolution affects the precision of intersections when flattened. Gradient and mesh resolution should generally be set between 150 and 300 ppi, because the quality of the gradients, drop shadows, and feathers do not improve with higher resolutions, but printing time and file size increase.

Converts all type objects (point type, area type, and path type) to outlines and discards all type glyph information on pages containing transparency. This option ensures that the width of text stays consistent during flattening. Note that enabling this option will cause small fonts to appear slightly thicker when viewed in Acrobat or printed on low-resolution desktop printers. It doesn’t affect the quality of the type printed on high-resolution printers or imagesetters.

Converts all strokes to simple filled paths on pages containing transparency. This option ensures that the width of strokes stays consistent during flattening. Note that enabling this option causes thin strokes to appear slightly thicker and may degrade flattening performance.

Ensures that the boundaries between vector artwork and rasterized artwork fall along object paths. This option reduces stitching artifacts that result when part of an object is rasterized while another part of the object remains in vector form. However, selecting this option may result in paths that are too complex for the printer to handle.

note: Some print drivers process raster and vector art differently, sometimes resulting in color stitching. You may be able to minimize stitching problems by disabling some print-driver specific color-management settings. These settings vary with each printer, so see the documentation that came with your printer for details.

Preserves the overall opacity of flattened objects. With this option, blending modes and overprints are lost, but their appearance is retained within the processed artwork, along with the level of alpha transparency (as when you rasterize artwork using a transparent background). Preserve Alpha Transparency can be useful if you are exporting to SWF or SVG, since both of these formats support alpha transparency.

Generally preserves spot colors. It also preserves overprinting for objects that aren’t involved in transparency. Select this option when printing separations if the document contains spot colors and overprinted objects. Deselect this option when saving files for use in page-layout applications. With this option selected, overprinted areas that interact with transparency are flattened, while overprinting in other areas is preserved. The results are unpredictable when the file is output from a page-layout application.

Blends the color of transparent artwork with the background color to create an overprint effect.

Preview which areas of artwork will be flattened

Use the preview options in the Flattener Preview to highlight areas that are affected by flattening. You can use this color-coded information to adjust flattening options.

Flattener Preview panel overview

You use the preview options in the Flattener Preview panel to highlight the areas affected by flattening artwork. You can use this information to adjust the flattening options, and even use the panel to save flattener presets. To display the Flattener Preview panel, choose Window > Flattener Preview.

You can control the speed and quality of the preview image by selecting an option from the panel menu. Select Quick Preview to compute the quickest preview; select Detailed Preview to add the option All Rasterized Regions to the Highlight pop‑up menu (this option is more performance-intensive to compute).

About transparency flattener presets

If you regularly print or export documents that contain transparency, you can automate the flattening process by saving flattening settings in a transparency flattener preset. You can then apply these settings for print output as well as for saving and exporting files to PDF 1.3 (Acrobat 4.0) and EPS and PostScript formats. In addition, in Illustrator you can apply them when saving files to earlier versions of Illustrator or when copying to the clipboard; in Acrobat, you can also apply them when optimizing PDFs.

These settings also control how flattening occurs when you export to formats that don’t support transparency.

You can choose a flattener preset in the Advanced panel of the Print dialog box or of the format-specific dialog box that appears after the initial Export or Save As dialog box. You can create your own flattener presets or choose from the default options provided with the software. The settings of each of these defaults are designed to match the quality and speed of the flattening with an appropriate resolution for rasterized transparent areas, depending on the document’s intended use:

is for final press output and for high-quality proofs, such as separations-based color proofs.

is for desktop proofs and print-on-demand documents that will be printed on PostScript color printers.

is for quick proofs that will be printed on black-and-white desktop printers and for documents that will be published on the web or exported to SVG.

Create or edit a transparency flattener preset

You can save transparency flattener presets in a separate file, making it easy to back them up or to make them available to your service providers, clients, or others in your workgroup. In InDesign, transparency flattener preset files have an .flst extension.

Export and import a custom transparency flattener preset

You can export and import transparency flattener presets in order to share them with your service providers, your clients, or others in your workgroup.

Rename or delete a custom transparency flattener preset

Flatten transparency for individual objects

The Flatten Transparency command lets you see what your artwork will look like when flattened.

Rasterize all artwork during printing

When you print to a low-resolution or non-PostScript printer, such as a desktop inkjet printer, you can choose to rasterize all artwork during printing. This option is useful when printing documents that contain complex objects (such as objects with smooth shading or gradients) because it reduces the possibility of errors.

What's next?

We've got you started on how to print and save transparent artwork in Illustrator. Take a step forward and learn how to trap color between objects in Illustrator.

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