Scrappile, when enlarging patterns I use Rapid Resizer and even with a PDF there is a way to do it. You open rapid resizer and then go back to the PDF and make sure you have the entire pattern on the page even if you need to reduce it to 50% you want the entire pattern on one page. Then center your pointer of whatever it is called on the pattern and hit your print screen key. Then reopen RR and you hit the paste key and the pattern is now in RR and you can size it as large as you want. This works for me and if needed you can make it darker and the lines show up well most of the time.
If you already know about this sorry to take up your time on it. Just what I use to do larger patterns from small ones.
jim
penquin