Hatching not plotting to PDF correctly

[jamesG84QZ]

Hi All, 

I've used hatching for the detail on the front elevation of a building (brick pattern). I made it more transparent to make the drawing less 'busy', which worked on the computer, but when I either plot from AutoCAD, or convert to PDF, the hatching loses its transparency and ends up very bold as if there was no transparency ever applied. 

I've attached the said PDF, as well as a screenshot from the AutoCAD software. 

Any ideas on what I'm doing wrong?

Thanks in advance!

James

[h_s_walker · Accepted solution]

Is the setting ringed in the image below ticked?