Open the pattern and choose Send from the Rapid Resizer's File menu.

If you want to send it to a print shop, choose Send to Print Shop from the File menu. Or choose Export to make a standard image file that you can send to them manually. Unless you want them to print the colored version of your image, first uncheck Show Colors in the View menu. When you're having a shop do the printing, the Rapid Resizer isn't contributing much. It just helps you scan and prepare the image. The shop is doing the "enlarging".