Checking how long a C# label can be seen

Question

I'm trying to make a template form that prints out a string in the middle, this string will be in a label or a textbox (still figure out which would be better there).

What I need to do is get the string to write to the label, then it's going to print out. After that, I want the label to display more of the string.

I'm thinking of doing it like this.

Write string to label
Print
Start a loop
Remove portion that was written from string
Erase label content and write in it again
Print
Loop until full string is written

I am however a bit confused on how to tell how much can be seen by the user. Is there a visible text option, or some command I don't know of, that would do this? Or anyone have an idea.