Maps created in ArcMap can be exported as an Adobe Illustrator (.ai) file. This is done by navigating to File > Export Map, and selecting to Save as type AI.
To ensure data is exported successfully, this article provides guidelines to consider when exporting to Adobe Illustrator. Not following any of these criteria may cause issues in Illustrator, such as when the layers are rasterized and display as a grouped image.
Because ArcMap uses Microsoft's standard graphic engine (Graphics Device Interface, or GDI), it is forced to output maps containing transparency as bitmap imagery. This is because GDI does not support transparency. It is recommended to export the files as vector data by removing the transparency from the layers in the data frame, and setting the transparency or modifying the color in Adobe Illustrator.
Symbols, such as Picture Fill Symbols and Picture Marker Symbols, are rendered as rasters in the output. When these layers are rendered, other layers beneath them in ArcMap's Table Of Contents are flattened and rasterized.
Replace the Picture Marker symbols with font-based vector marker symbols, and Picture Fill symbols with simpler vector fills.
There is a limit to the amount of vertices that can be exported. It is possible to have one layer with 1,000,000 vertices or fifty layers with 10,000 vertices in each layer. Merging these layers into less layers does not change the underlying data and therefore does not change the vertex count.
When there are too many layers, it is possible to turn off some of the layers before exporting the map - layers that are turned off do not get exported. It is recommended to move raster layers to the bottom of the drawing order or remove the layers before exporting the map.
In the Export Map window, under the General tab (see image below), the setting for dots per inch (DPI) reflects the resolution of the data being exported to Illustrator (as pixels). For the map to appear in illustrations at the same dimensions as in the ArcMap layout, set the DPI around 150 to 200. If the map is intended for users to zoom in on the illustration, set a higher resolution to the map. After exporting the map, check the detail in Illustrator to ensure it meets expectations and, more importantly, that no data is lost.
To prevent the rasterization of the map, select the Vectorize layers with bitmap marker/fills option, and check the Convert Marker Symbol To Polygon check box to convert raster markers/fills to polygons.