Thanks… you explained really well. I didn’t understood a word but your explanation made it obvious. Just a doubt, what chemical you used to etch copper and why you added metal fillings later?
Sorry for the late reply. I'm not good at English. sorry. Things used for etching → Oxidol, citric acid, and salt What you put in last → Aluminum foil (for waste liquid disposal) Adequate ventilation is required. I'm not sure if the sentence is correct. Sorry if I'm wrong.