I try something I’ve never tried before - etching stripboard/perfboard/veroboard in ferric chloride etchant.
The idea was to create a breakout board for a Quectel L80 GPS module (based on the MediaTek MT3339 chip). This module has a 0.1in (2.54mm) pin pitch, which is rare for recent GPS modules. Most have 2mm or even finer pin spacing. This module’s pin pitch is a good match for common 0.1in stripboard.
I run into all sorts of dramas with cold, weak etchant that over-etched in places while under-etching in others. But a second attempt yielded an acceptable result. All’s well that ends well.
Would I use this technique again? Probably not. But it was an experiment worth trying.