~ A guest blog post by ADGISer Barry McLane

I’m a big fan of Adobe Creative Suite, and have been working with Photoshop and Illustrator for some time. Last fall [in GIS 321] I discovered that ArcMap can export to Illustrator (AI) files, and I’ve since been finalizing all of my maps in Illustrator. The publishing capabilities of ArcMap are decent – especially in contrast with other GIS software – but the output quality eventually caps out.

Some of the graphic design features of Photoshop and Illustrator are absolutely necessary to reach a high level of cartographic quality.

Color management and opacity settings – to name only a few – are areas where Illustrator really outshines ArcMap. The library of raster effects in Photoshop are really useful as well, and can give maps a very customized look.

I recently had the opportunity to work with Tourism Rossland, and created maps for their new road biking brochure. I sourced all the spatial data, and compiled the map layers in ArcMap 10.2 using fixed extent data frames for each map. I then exported the raw layers into Photoshop (rasters) and Illustrator (vectors). This workflow offered up a good change of scenery, as 90% of the work was done using non-GIS software.

The fixed extend data frames are really key. They enable the user to continually make changes/additions in ArcMap, and import them into the existing Illustrator file without the need to re-align layers. Illustrator maintains the grouping of layers, which is very helpful.

Map elements, such as scale bars and legends, are also separated into groups.

I used Illustrator to do the vector work: feature symbolizing, text labels, symbols etc., and Photoshop to build the base maps, which are a composite of multiple hillshade and DEM tiles. I exported the hillshade and DEM rasters as TIFF files, and stacked them into a single Photoshop (PSD) file. This allowed for maximum flexibility with the tone and contrast of the basemaps. The elevation profiles were made using the Strava route planner. I imported screenshots of the profiles into Illustrator, and used them as templates to create new profiles from scratch.

This project was a great learning experience for me, and I feel lucky to have worked with such professional people. The graphic designer, Shelley Ackerman, and author Terry Miller really did a bang up job. The brochure design is top notch, and the tongue-in-cheek ride descriptions are hilarious. It has been published as an 8 panel, double folding brochure that Tourism Rossland distributes to events and storefronts across the region, to promote Rossland as a road cycling destination.

The process of exporting ArcMap documents into Illustrator isn’t without it’s nuances, though. Here’s a few tips/lessons that I’ve learned over the past 6 months:

  1. In ArcMap, no layers can contain any level of transparency, otherwise they will be exported as an un-editable full-page raster. This is usually the main source of problems when exporting to AI.
  2. The resolution at which you export will also affect the vectors, which strays from the traditional concept that vectors are “resolution independent”.
  3. Only one raster image can be exported at a time. Multiple exported raster layers will be flattened into a single layer on the AI side. I find it simplest to export rasters as TIFF files, and place them in the AI document separately.
  4. The layers nest themselves in groups in AI, and 2 clipping masks are created for each layer. The concept of clipping masks can be annoying and difficult to grasp at first, but they are ultimately what allow users to add newly exported layers without the need to re-align. More info on Illustrator clipping masks here.
  5. Keep features simple when exporting, and do all the symbolization in AI. No need to duplicate the process.
  6. Exporting text from ArcMap to Illustrator is in general pretty buggy, so I just don’t bother. I do the annotation work once in Illustrator, where it is more flexible anyway.
Check Barry’s fine work in detail on his own site.  Front & back of the brochure