Report Builder export low quaility

Hi everyone! 

I´m working in a paginated report, this report have a especific size and margin (it´s be use for print in a A4 paper).

My problem is if I do a graph with a legend or font size lower than 5 and export the report to Word, the graph quality is very poor , This is because Report Builder transform the graph to an low quality imagen, and this only happen when I export to word however if I export to PDF the graph have a good quality.

Is it possible to change any configuration on the report builder or in the workspace to force when I export to word to change the quality for the image?