Home etching is an error prone process, especially if you go down to (what looks like) 0.8mm pitch QFP’s
With 10 PCB’s for EUR10 from China you also get much better PCB’s then you can hope of making yourself (Double sided metalized through holes 2 solder masks and 2 silk screens and the nasty FR4 stuff cut to size) All this with just a few mouse clicks…
With home etching there are a lot of variables to take care of, and each process has it’s own pro and con’s.
Marco Reps has experimented with UV dry film on the PCB and a UV led or laser for directly drawing into the dry film. BigClive also has made a nice youtube vid of his process of home-etching PCB’s.
There is also milling, but it’s also difficult to get the required resolution.
Yet another method is with a pen plotter and a thin felt tip pen with etch resistant ink, and then draw directly on the PCB. This has been used with success by some as early as the 70’s.
In these “modern times” “high resolution” is often used as a gimmick word and manufacturers of (consumer grade) electronics do all kind of stuff to make stuff look good to casual observers (such as smooth lines) but not real accuracy. Also multiple layers of “enhancement” of pictures by photo programs, laser printers and other equipment.
One way of fine tuning your process is to make a test PCB with different pitch components and track widths and clearances, and get that PCB through the whole process and look at the final etched result. I’ts probably the fastest way to a process that works for YOU.
SVG is also a pretty common format. You can probably also do your own post processing to modify line widths or convert to a format that your printing service accepts.