Printing RSS on printer

Thanks for your advise, Nick.
So, you're recommending line by line.

In this case, how do I prevent memory leak?
With a given example from Arduino,

String rss; //without defining size

rss = "1st line news feed";
printer.print(rss);
rss = "2nd line news feed";
printer.print(rss);

Is this what you recommend?

Thanks in advance