[Solved] Inverted (negative) text on silkscreen

[rob]

I saw (= found) this posting: Negative Silkscreen - #3 by bobc

I’m quite happy with the solution here!
I did clone the kicad-utils and see that ‘subtracting’ from a gerber layer works nice, also in Kicad 6.

I added a bash script that automates it a little bit more:

#!/bin/bash
# Silkscreen gerber file post-processing ("subtract" contents of a second file, e.g. to create inverted text)
# Note: overwrites existing F_Silkscreen.gbr!
# automatically takes the project name from the prefix of the *.gbrjob file (in output/ folder)
subtract_layer=User_Comments

cd output
name=$(ls *-job.gbrjob)
prj=${name%%-*}
echo project name: $prj
python ~/git/kicad-utils/scripts/gerber_combine/gerber_combine.py $prj-F_Silkscreen.gbr -s $prj-$subtract_layer.gbr -o $prj-F_Silkscreen.gbr
cd ..

Perhaps useful to modify & incorporate this with any work.
Use case example in a dense pcb where two references cannot be place beneath the associated components:
(uses another component as intuitive location indicator)

Would be nice to see it one day as a built-in feature.

[jmk]

Negative Text??

Is the example you give U1?

[gkeeth]

@rob

Would be nice to see it one day as a built-in feature.

It’s a built-in feature in soon-to-arrive v7

[jmk]

It is called “knockout”
Available on PCB not Schematic.

[greg_m]

For KiCad v6 there is a plugin for that:

GitHub - gregdavill/KiBuzzard

I think there is another one doing similar things, but forgot the name now and don’t have it installed at the current machine (work). Will let you know later.

[rob]

What’s in a name!
But seriously, woudn’t it be not better named ‘photo-negative’ or ‘cut-out mode (with filled shape)’?

[rob]

@jmk Thanks voor the ‘intuitively’-proof. Which also is a hint for me that the documentation along the hardware should point out this workaround for references not in immediate component vicinity.