SSRS Chart Resolution in PDF Exports

Hi all,

The background to my query is that I’m working on a project for a not for profit company where the end users are across the world in developing countries, so black and white printers are normal.

I am experiencing a problem with SSRS 2012 that when I export to PDF the resolution of the background patterns used on the charts is not high enough, and when printed on a black and white printer it is not possible to distinguish them.  Note this is for charts, not images.  

The problem is mentioned in multiple other threads such as:

http://social.msdn.microsoft.com/forums/sqlserver/en-US/0acdf8bb-41a8-4cb7-8d22-ae4297b15243/background-patterns-and-exporting-to-pdf (which shows a screenshot demonstrating the problem).

http://stackoverflow.com/questions/223094/how-to-export-ssrs-charts-to-pdf-at-high-resolution

http://stackoverflow.com/questions/3578087/has-anyone-figured-out-a-way-to-render-a-reporting-services-report-at-a-resoluti

and on:

https://connect.microsoft.com/SQLServer/feedback/details/679384/pdf-render-setting-set-to-300dpi-remains-at-96dpi-for-any-chart-exported  (I'm unconvinced that the answer to this makes sense).

I've also seen articles from Microsoft staff which state both that the PDF renderer always renders charts at 300dpi and others which state 96dpi. The latter seems closer, although when I then edited the PDF it looked like it was only 72dpi.

I have tried:

- editing the Rsreportserverconfig file and setting HumanReadablePDF to true and false and the only difference seems to be that the report size is larger

- editing the Rsreportserverconfig file and setting DpiX and DpiY values.  These seem to make no difference, having tried them at a variety of different settings.

It does seem that my only working option for higher quality charts is to export to TIFF instead of PDF, but this is not as convenient for the end users (these reports are usually downloaded into the country head office as PDF, and from there may be mailed to other colleagues who probably have poor or intermittent internet access). 

My questions are therefore:

Has anyone successfully forced a higher resolution for charts in PDF by using the DpiX/DpiY values or any other method?

Has this changed in SSRS 2014?

Many thanks for your assistance, CarrieAnne