Excellent suggestion. I’m well versed with GIMP already.
Let you know how it goes.
EDIT : SVG printed from GIMP with the Raster Drivers gives much cleaner results!.
I’ll try it with my Canon Driver.
Ok I tried
SVG - GIMP - Canon Driver
The results were nice and clean. Even with ‘Plain Paper’ at 2/5 quality. (1/5 is restricted to Glossy Paper at 4"x6"… MEH. Last week I cut plain paper to that size just to enable to setting but today its not having any of it!?)
The key here, I think, was to set the Resolution of the image on import. Its default was 90dpi. Windows desktop has 72dpi default I do believe. This would account for the mismatch. Anyway, I scaled this up as much as I could in multiples of 90 until it was just less than 1200 (which my printer claims to work in), so I set it to 1170dpi square.
Interesting point to note is that in the ‘Image Settings’ which appears as a tab in the Print pop-up if you change this dpi resolution here it will actually scale the image…so it has to be done on import.
Another interesting observation is that when I accidently scaled my image and it came out at half the size, the quality of the image still far exceeded the original full scale images which I struggled with under PDF and Direct Print from Kicad options.
Thanks @BobZ
Im nearly there!
I also Emailed Canon to ask them if they have an alternative Raster style driver suitable for CAD as their drivers were painfully and woefully inadequate. I’ll report when they reply.
GIMP unfortunately doesnt have full support for SVG files although it can open and print them nicely. Interweb spits the word “Inkscape” at me when I conduct relevant searches. Apparently this is for working with SVG files. Ill check it out.
Tried Inkscape. GIMP prints in better quality.
I might settle for this. The scattering can be cleaned up with a scalpel under the microscope, later.
Here’s some of what I was talking about earlier.
Even in maximum contrast the files produced by Kicad contain unclean edges and pixels which are grey. It does seem that I can clean this up in GIMP but in my opinion this should not happen at all.
The grey halftones might be a (mal) function of anti-aliasing? I think I always turn that off where possible. If I have something drawn in 1 bit B&W, I do not want to get halftones.
I just printed the same board as my post # 19. I printed to a PDF using the built in “Microsoft print to PDF” driver.
This is a screenshot of the result zoomed to 6400% !
Again I’m using Kicad 5.99
Indeed, I do try to switch off all anti-aliasing functions for this. I do wonder how far my hardware gfx comes in to play with relation to windows, the kicad program and eventually the print drivers.
Perhaps that’s where I should have started? Do you use Hardware Gfx options? Also, what size are your C6 and C8 caps, if you don’t mind my asking? I’m using 0603. Bit of a challenge, it seems.
I’m wondering if you can print PCB layouts on a household printer with 0.5mm pitch footprints and then use it for etching. And to get that to work reliably would be even more complex.
If you’re serious about wanting to make relatively high resolution PCB’s at home, then using a 3D printer with a laser diode to directly develop photo sensitive PCB’s is probably a much better option.
In the video below, Maco Reps uses a Cetus3D printer (which is relatively cheap, and almost surely the cheapest with decent linear rails. He’s getting quite good results with his setup.
There are also other options. If you search a bit around on Youtube it’s easy to find some.
This is what I get from Print to PDF if I initiate it from the Print screen
That coating of bright fuzz that lines the traces like a toxic mould causes some terrible results on my printout 
No it’s not.
(At least not on Linux)
Printing to .PDF preserves the vectors.
I used: Pcbnew / File / Print and then Print to File for the output, and then opened the created .pdf in Inkscape (which is a vector drawing program that works with .SVG files natively but can also import .PDF and some other formats)
That is probably the problem.
“Print screen” takes pixels from your monitor. and those are simply not usable for artwork output. Just the scaling alone is a nightmare. Even if you disable anti-aliasing in KiCad there can still be other software that interferes.
So I conclude that KiCad works correct, but you have to get your workflow in order.
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This is what I get if I do a Plot to PDF then open the PDF in Adobe and from there Print to PDF
These are 0.25mm traces.
So yes 
Print to PDF has perfect data retention.
The first time I tested this my results were not so good. I think in that time the difference was that Ive installed Adobe Acrobat Reader since. Must’ve come with improvements to PDF capabilities on my machine.
Yes… it definitely was!! 
I’m Windows 10. I’ve been experiencing some element of my system, rather evasive, that is degrading the quality of my printouts and my PDF’s. I’d even tried inkscape but I was always experiencing the same issues.
After installing Abobe, I went into the Preferences and switched off all the Rendering smoothing options and set the program to a default of 1200 pixels per inch. It’s definitely solved some of the problems I’d been experiencing with PDF’s systemwide, curiously. My OS installation was quite fresh. Base PDF handling in windows has its limitations it may appear.
This may or may not translate through to my printouts. Im yet to see.
The screen does not come into play when I print to PDF.
Then:
I don’t mean to ‘Print Screen’ as some kind of option 
I mean the Popup print dialog just like the one that exists and that everyone uses in Windows, as above.
Yes, just probably not my crappy inkjet
Only if the graphics are in vector format
So, my PCB’s aren’t as “fine” as those being discussed here, but I just tried doing a “Print”, and selected the Microsoft “Print to PDF” printer. As I zoomed in on my DIP pads, I could see nasty stepping on the rounded corners.
So, I then tried to “Plot” and selected “PDF” as the output format: the image quality was MUCH better.
I bet part of the issue is to do with the Microsoft “Print to PDF”, and how it is (internally) set up. Just because it says “Microsoft” doesn’t make it any good.
I used Microsoft “Print to PDF” with excellent results.
What seems to be happening, but I don’t know why, is:
- You seem to be getting raster graphics (i.e. bitmap for some sort)
- My print to PDF was in vector graphics which can be scaled to huge dimensions without any “stepping”
What program are you viewing your PDF with?
Yes this is much what I was experiencing, but I dont think that Print to PDF is actually the culprit. There are other factors involved.
Refer to the simple diagram on this page. It shows that your Application can communicate directly with printer of go through the ‘GDI’. I think the latter case is the one in which results are spoiled but its tricky to know exactly what process is being used. Too many Chiefs… sort of thing.
Out of curiosity, do you have Acrobat Reader installed? Is so, have you checked the default options for Antialiasing/Smoothing and default DPI?
With Acrobat installed, Windows seems to then refer to it for all its PDF handling operations instead of what shipped with Windows, with much improved results.
The other Printer based issue is somewhere along the line, even with Vector graphics, the end result has to be converted to Bitmap in order for the printer to actually print it out as it can not handle the Actual Vector drawing like a Plotter can, which has relatively free movement around the 2D plane.
With regard to Blurred edges and bad lines, although GIMP produced good results after some cleaningof the image I did notice that anything I imported to GIMP became blurred even if it was not apparent in other viewing softwares. GIMP itself was adding the blurred edges. It appears that some software packages interpret the Image itself rather than producing pixel perfect reproductions.
The quickest solution to the problem is simply to not use PDFs at all and regard them as being insufficient for this task.
Use SVG format instead. Although I didnt get great results with Inkscape at first, I perservered; altered the default DPI settings in the prefs and now the results are astoundingly accurate. Inkscape also allows you to select outputs of Vector and Bitmap at a selectable DPI.
Ive got my print accuracy down to something I can use but at this scale I am seeing the inaccuracy of my printer, itself, with plain to see mislocated Ink-dots.
I figure that given that you need to double up or even triple up the laminations in order to provide enough light-blocking then the spurious ink-dots may not actually be an issue as alone can not block enough UV and the copper will expose anyway.
It does take a lot of practise but it is possible to clean up your tracks with a microscope and scalpel. Run the point of a straight edged scalpel through the voids to make sure there are no mis-connections. Warning : This operation requires you to be able to hold your breath for extended periods of time 
Perhaps you are on to something. I had excellent results printing to PDF. I have never installed Acrobat Reader (or Acrobat anything). The results I posted were from Sumatra PDF Reader.