A few years ago (not many) I used to burn copper plates using acetic acid, a.k.a. vinegar. I was somewhat concerned about using stronger acids so it was OK to use another acid, even if it was soooo sloooow. If you were patient you could get to have decent boards using 50mil traces (or even thinner). But it required keeping a good temperature on the copper bath and regulating the ratio vinegar/hydrogen peroxide continuously, adding a little salt from time to time to speed things up.
One day I saw an article about cheap Chinese PCB fabs (I think it was DirtyPCB by Dangerous Prototypes) and I decided to design my own board and send it to fab. I used Eagle (I still use it although I’m learning KICAD) and the learning process was significant. But at the end I managed to get something. I learned to use copper pours, to correctly label the board, to create my own parts, to avoid auto-route, to use design rules and create gerbers,…
And over time I have tested different fabs. I’m not an expert by any means but I wanted to write a bit about them here. The basic order I usually do is a 10 units, under 50x50mm board, 1.6mm thick, 1oz copper and HASL Lead Free due to RoHS rules in the EU. The prices and options below are based on these settings.
One more thing. I reckon these suppliers are good enough in most cases for small batches, testing boards or DIY projects. Some EE are concerned about the quality of the boards and they prefer EU-based (or US-based) fabs. I cannot offer a good reason to use these manufacturers here or to not use them in professional/industrial projects.