Here's a step by step Tutorial
You know, there are sometimes other systems putting textes in your system and the customer want to print it out without a difference in it.
Normally the Form has 72 Characters printing in a Line.
So, here's a possibility:
It's a german system, So, the Settings are below the hat-symbol
The copy is from the SAP-Form "SYSTEM"
Create your own Sapscriptform with the dimensions you need. Perhaps another Font, recommended is Courier.
Then go to SE75
Display the Text Objects and IDs, search your Object, you want to change. This is what you see ( It's just an example, so don't be surprised by not finding the same names)
Last column, there is the form, used for the printouts
Change the Form to your new developed and the output will match as you mentioned.
If there is something missing or not that good to understand, just let me know.
Regards
Florian