It is a long time since I made use of transparent map backgrounds, and on trying just now I think it is no longer working (at least in 5.3.10, 5.3.9 and maybe earlier versions I get white backgrounds instead).

Or perhaps I am making a silly mistake?

I thought the problem might be the same as the bug in 5.3.5 when this feature was first introduced

http://article.gmane.org/gmane.comp.gis.therion/2349/match=map+bg+transparent

but it seems I get opaque white backgrounds with either syntax…

within an explicitly defined layout;

layout LayoutMapBulmer_System            

colour map-bg transparent

endlayout LayoutMapBulmer_System            

or as part of the export map command;

export map   -projection [elevation 270 deg] \

  -layout LayoutMapBulmer_System             \

  -layout LayoutMapBulmer_SystemElev       \

  -layout-colour map-bg transparent   \

  -output ./Output/MapBeautBulmerLate08System_Elev.pdf

You can test this by creating a pdf map with a transparent background and inserting it into another map with ‘map-image’. 

Does anyone else find that transparent backgrounds are not working?

Bruce