Negative PCB output for Photoresist

I am newbie to Kicad and running linux mint. I got my project almost done but I am trying to figure out how to get a negative view of traces so I use my Negative photoresist?? First I tried ploting it in pdf form but it prints only some of the traces and they show up on the screen before the print… Anyone could suggest any help ??
Also Happy 4th of July

1 Like

In the pdf plot (not print, plot) menu there is an option “negative plot”. This creates a pdf that you then need to print. You might need to play around with your pdf program until you get the correct scale.
I remember there was a topic on here that explained that but i can’t find at the moment. (If i find it later i will post link to it here.)


Hi, I’m trying to generate the negative of layer, but the negative check box in the plot window is disabled.

I’m using the latest nightly build of Kicad for ubuntu.

Am I missing something ?

Yep, I missed something…
in order to the “negative plot” checkbox to be enabled you need to select PDF / SVG in the “plot format” combo-box. :blush:


New to KiCad and as Ranger14 has stated I am also using Negative resist. I have used the suggestion that Rene posted and was able to print the Bottom Layer OK.
My question is how can I add the holes to the print? This will make for centreing for easier drilling especially with large mounting holes.
Also can different layers be added together like the B_Cu layer and the Edge_Cuts for odd shaped PCB’s.
Thanks Mike

If you’ve got PDF outputs of the Cu_F, CU_B and Edge_Cuts, then you can:

  1. Using Inkscape or other (I’ll use Inkscape for this example), Open the Cu_B

  2. Import the Edge_Cuts

  3. Overlay them so positions are as desired.
    Click the Edge_Cuts graphic and set it’s background to X (meaning, None). That makes it Transparent except for the White Lines you’ll setup, indicated below.
    Save as a new PDF.

For the Cu_F, probably only want the circuit but, can repeat above if wanting Edge_Cuts, as well.

Image below shows PDF for Cu_B with Edge_Cuts. The Holes are part of the Edge_Cuts layer (that’s my preference).

• Ensure proper scaling of PDF output.
• Set the Edge_Cuts layer to White color. That makes the drawn lines White.
• Set the Line-width of the Edge_Cuts to something like 0.4mm. Best to do it in Board Setup but can hassle doing it line-by-line in the PCB.

EDIT - you can set the Drill Marks Small in the plot panel… they look like last screenshot - should have done it before loading into Inkscape… but, you get the point…

1 Like

It’s quite easy to produce negative output with drill holes and EC lines.
Take a look at the following screenshots:

Notice that the Drill marks are selected as Small (just to act as initial guides for manual drilling) and unchecked “Exclude PCB Edge…” (EC) layer.

1 Like