Moving Layers Between Photoshop and Illustrator

Thanks to the great similarities between how layers are handled in Photoshop and Illustrator, it's possible to move a layered document from Photoshop to Illustrator, or from Illustrator to Photoshop, and retain much of the layer structure that you've carefully created. During inter-product importing and exporting, Photoshop and Illustrator retain layers and their components, as well as type, masks, and other elements, as much as possible. However, layers will be merged if retaining them would compromise the appearance of the resulting file. This makes it possible to move artwork back and forth between the two applications, using each application for the kind of work it does best.

Layers from Photoshop to Illustrator

The best way to move a Photoshop image into Illustrator is to use the Illustrator Place or Open command.

• To place a Photoshop image as a sublayer on the currently selected Illustrator layer, in Illustrator choose File > Place, and select the Photoshop image. Uncheck Link to embed the file (you cannot edit a linked file).

• To create a new Illustrator file with each Photoshop layer converted to a new Illustrator layer, in Illustrator choose File > Open, and select the Photoshop image.

Whether you place or open a Photoshop image, in the Photoshop Import Options dialog box (Figure 12-17), select Convert Photoshop Layers To Objects and Import Hidden Layers, and click OK.

Figure 12-17. Placing a layered Photoshop image gives you the option to convert Photoshop layers to Illustrator objects.

If you opened a Photoshop image, a registration rectangle appears on the bottom layer around the image bounding box. (You can release it by choosing Object > Crop Area > Release.)

Keeping Type and Layers Editable

Placing a Photoshop file in Illustrator maintains the editability of type, and converts each Photoshop layer to a single embedded image (as shown in the Links palette) when the Convert Photoshop Layers To Objects option is checked. Any Photoshop layer groups will be imported as Illustrator sublayers. Layer opacity and blend mode settings will be retained when possible. Figure 12-18 shows a simple layered Photoshop file with type and image layers converted to Illustrator objects.

Figure 12-18. Photoshop image (left) contains image layers and a type layer. When converted to Illustrator objects, the type remains editable (right).

Merging Layers with Unsupported Features

Illustrator doesn't support all Photoshop layer features. When Illustrator imports files with the following layer features, it merges the layers automatically, without alerting you:

• Adjustment layers.

• Layers with certain blending modes (Color Dodge, Color Burn, Difference, Linear Burn, Linear Dodge, Vivid Light, Linear Light, or Pin Light.)

• Layers that use layer effects (depending on specific details of the transparency and blending mode options chosen).

• Layer sets that use the Dissolve blending mode.

Once merged, these layers are no longer editable.

Importing Type

Illustrator can import point type (single lines of type), text frame type, and type on a path. However, type that is warped with the Warp Text dialog box or the Warp transformation command must be rasterized during import. Likewise, type with any layer effects will be turned into pixels.

Tip: Reapply Effects in Illustrator

When you're bringing Photoshop type into Illustrator, remove any warp or layer effects in Photoshop. Then reapply the effects using commands in Illustrator.

Converting Masks

Photoshop mask features layer, vector, and clipping masks are converted to equivalent Illustrator masks.

• Photoshop layer masks become Illustrator opacity masks (Figure 12-19). To see the mask in Illustrator, expand the collapsed list of layers imported from Photoshop, target the layer with the opacity mask (indicated by a dashed line under its name), and then use the Transparency palette to view the opacity mask. The layer thumbnail and layer-mask thumbnails match their Photoshop counterparts. (For more on opacity masks in Illustrator, see Chapter 11, "Transparency.")

  Figure 12-19. A layer mask in a Photoshop image (left) is converted to an Illustrator opacity mask that can be viewed in the Transparency palette.

  

• Vector masks and clipping masks created using vector shape layers become compound shapes in Illustrator (Figure 12-20). Use commands in the Pathfinder palette menu to release or expand the selected compound shape.

  Figure 12-20. A vector shape layer in a Photoshop image (left) is converted to an Illustrator compound shape that can be edited in the Pathfinder palette (right).

  

• Clipping masks created using a pixel layer (in which the boundary of the non-transparent pixels defines the clipping mask) are rasterized when converted to an Illustrator object mask. (In contrast, clipping masks created using a vector shape layer, in which the vector outline defines the clipping mask, are retained along with the layers they mask.)

Layers from Illustrator to Photoshop

Just as you can move layered files from Photoshop to Illustrator, you can export layered Illustrator files to Photoshop to continue editing them. Before exporting to Photoshop, it's helpful to set up your Illustrator layers to make them as editable as possible in Photoshop. Do this by creating sublayers and compound shapes.

Creating Sublayers and Compound Shapes

Think ahead to which objects you want to maintain as vector in Photoshop. Move those objects to separate sublayers in Illustrator, and then convert them to compound shapes.

We'll use as an example a simple Illustrator graphic that contains three kinds of type point, type on a path, and text frame. It also contains some stars that we'd like to move to Photoshop to apply Photoshop layer effects (Figure 12-21, left).

Figure 12-21. Illustrator artwork with type and star shapes (left). To keep the stars as editable vector objects in Photoshop, move them to sublayers and convert them to compound shapes (right).

We moved each star to a separate sublayer. We then selected the path of each star on the Layers palette (Figure 12-21, right) and created a compound shape by choosing Make Compound Path from the Pathfinder palette menu.

Preparing Compound Shapes

Before export, Illustrator shapes with strokes must be changed from the default Miter Join attribute to a Round Join in the Stroke palette (Figure 12-22). If the stroke join isn't properly converted, the object will be rasterized rather than converted to a shape layer. When correctly converted, the stroke is applied as a stroke effect applied to the shape layer.

Figure 12-22. Choosing a Round Join before converting Illustrator shape with stroke.

Before exporting compound shapes, also eliminate any brushes, dashed strokes, or graphic styles applied to them, to prevent the objects from being rasterized.

Exporting as a Photoshop File

To export an Illustrator file to Photoshop, choose File > Export and select Photoshop (PSD) as the format. In the Photoshop Export Options dialog box (Figure 12-23), choose from the following options to retain quality and editability:

• Color Model. Choose the same color model as the Illustrator file. Changing to a different color model will flatten the file when it's converted.

• Resolution. For objects that will be rasterized when exported, select the Photoshop image resolution.

• Export As. Select Photoshop CS2. Selecting the other choice, Photoshop 5.5, limits you to point type and 100 layers.

• Write Layers, Preserve Text Editability, Maximum Editability. Choose all of these options to include layers, sublayers, and type editability. Top-level layers become Photoshop layer groups. Hidden layers become hidden Photoshop layers.

• Anti-alias. Select this option to smooth the edges of pixels, which is usually desirable.

• Embed ICC Profile. Check this to create a color-managed document.

• Click OK to create the Photoshop file.

  Figure 12-23. Exporting Illustrator art with Write Layers and Preserve Text Editability options to allow editing in Photoshop.

  

When the Illustrator file is exported with the Preserve Text Editability option selected, opening the file in Photoshop shows all the type on editable type layers (Figure 12-24, left). Point type, area type, and type on a path are all converted successfully. The figure also shows what happens if sublayers and compound shapes weren't created all the stars are rasterized onto a single pixel layer. Creating sublayers and compound shapes puts each star object on its own shape layer, with a vector mask so that it can still be edited in Photoshop as needed (Figure 12-24, right). Opacity and blending modes are also retained.

Figure 12-24. Illustrator type converted to Photoshop type layers (top). Putting vector objects on sublayers and making them compound shapes in Illustrator retains their editability in Photoshop (bottom).

Illustrator masks convert to Photoshop masks: Both "traditional" clipping masks and layer-based masks are turned into Photoshop shape layers.