What is the most profitable job for a printing house?

I suggest you learn printing. Printers in all printing houses have the highest wages. Offset printing means paper printing. The captain's salary of Heidelberg, Komori, Violet and Mitsubishi can get 6000- 10000 per month, but the study time should be at least 4 years longer. If you don't have acquaintances, you may not learn the essence. Think about it. If you fail, you can learn color printing, that is, plastic printing. You only need 6- computer printers with a captain's salary of 3600-6000 and ordinary printers with a salary of 2500-3600, which is not bad. I have been engaged in color printing for 7 years. I think learning this period will be effective, but you must be diligent and smart. I believe you will succeed! !