Thanks jimking.
I have looked a bit at some job descriptions as a retoucher and almost all lists some degree of prepress knowledge. Ofcause that is practicly knowledge, but i guess this is a topic i should start to look a bit at.
I didnt expect this forum to be about inkjet printers, it was more to show im not having those huge machines myself
I think the topic under prepress I could start to look into is more knowledge about pdf as a standart (this is a prepress topic right?)
//just saa there is a acrobat forum in here, i guess thats enough answer for me

I'm sorry if this is questions i should read from a manual somewere.