You need to adjust your PENS. Check what PEN # you are using and change them to BLACK. Assign that "pen set" to the VIEW that you place on your SHEET.
OPTIONS > ELEMENT ATTRIBUTES > PENS AND COLOURS
It's common practice to have number of pen sets.
At minimum have one that you work with within ArchiCAD ... I like to know that RED is 0.18mm thick, BLUE 0.25mm, GREEN 0.50mm etc ... it's easier to tell them apart than if everything is black and white.
Then you have a second PEN SET for you PDF publishing, with just blacks and greys etc.
Hope this makes sense.
ArchiCAD 10 - 25 | Windows 10
ARCHIcreate | Perth, Western Australia
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