Select Print from the Block menu to print the selected portion of the current file, rather than the entire file. A preview of the printout is shown first. It allows you to make some changes like which font to print with, which pages should be printed. You can also access the printer setup through the preview window. See the topic on File|Print for a full explanation of the print preview.
There are two key differences between selecting Block|Print in the menu compared with selecting File|Print and turning on the “selection only” in the print preview. The checkbox works at the level of a single line. If a line is partially selected, it is printed entirely. Block|Print, however, sends the exact selection to the print preview, and ultimately the printer. If you want to print a rectangular block then Block|Print is definitely more useful.
Syntax coloring may also be printed differently. Since File|Print sends the whole file to the print preview, the printed lines are colored the same whether you’re only printing the selected lines, or you’re printing the whole file. But Block|Print only sends the selection to the print preview. Syntax coloring will treat the selection as if it is a complete file because the rest of the file isn’t available to the printout. If your selection cuts through syntactic elements, they won’t be colored properly in the printout when using Block|Print.