Packed in plastic jars with a wide mouth (bucket).
You can pour water directly into the bottle, then pour the solution into another container and bring it to the desired concentration. This package is convenient and safe to use, securely closed with a screw cap.
Board etching.
For etching, use a glass or plastic container, such as a photographic cuvette. Put the board into the mortar with the pattern up, the entire surface of the board should be covered with the solution.
The etching process is accelerated if the vessel is shaken or heated. Pickling produces poisonous fumes, so work either in a well-ventilated area or outdoors. Periodically check the condition of the board by lifting it for inspection with wooden or plastic sticks; metal tools and fixtures cannot be used for this purpose.
After making sure that the foil in exposed areas has completely disappeared, stop the etching process.
Transfer, for example, using a clothespin, the board under running water and rinse thoroughly, then dry it at room temperature.
If you are going to use the solution again, drain it into a tightly sealed container and store in a cool, dark place.
Please note that the effectiveness of the solution decreases with repeated uses.