Anyone else noticed this? When I export a layout to PDF from ArcGIS Pro (1.4.1) at the default 120 dpi resolution, any text label halos are very poorly rendered in the final PDF output.
Now I was well familiar with this issue in ArcMap due to its different display pipeline, where low dpi (< 300 dpi) settings would not only lead to poor text label halo quality, but also loss of fine detail in the PDF output, and often even thin line objects not being exported at all and thus disappearing in the output.
I therefor always use some very high dpi setting in 100% vector maps (e.g. 3600 dpi) in ArcMap, so as to force proper rendering and higher quality text label halos output, and at least a minimum 450 dpi for combined vector and raster output.
However, due to its new architecture, Pro was supposed to solve these issues as far as I understood. Indeed, when looking at the true GIS vector data, the quality of the PDF output even at a low 100 dpi or so, is excellent.
Unfortunately, not for the text label halos though!... Look at the accompanying images (note: 800 or 1600% enlargement), which shows both a high res ArcMap output, and Pro output at different resolutions. Notice how at 120 dpi, the halos are rendered really poorly. Instead of nicely encircling the corresponding label characters, the halos appear skewed, shifted and e.g. the "i" dot is square instead of trapezium as it should be for the italic text.
Notice that with a 3600 dpi setting in Pro, the issues are completely resolved, and in fact, the halo rendering is even better than from ArcMap at the same resolution.
However, a not unrealistically low 300 dpi setting, still leads to big artifacts in the halos... This will be an issue when exporting combined raster + vector data, where you may wish to reduce output size by limiting the dpi setting. As for now, this will lead to poor text halo quality in the PDF output.
Note 1: for the full resolution images, open the attachments of the post instead of clicking on the images.
Note 2: the screenshots are based on Adobe Reader XI 11.0.19, so not the newer "DC".