Homebrew PCBs

Light bulb was a flop till I raised the length of time to 11 min in wood box under bulb approx. 12 in. I got two good to go tone control boards done today except etchant.Problem is also quality of dry resist film bought in china cheep. From 40 sec up to 9 min was included in all my research. What is all the hype of over exposure and what do I look for? All traces are under the size of a header pad by quite a lot, smaller than a .046 transistor pad I beleive the measurement was.